Update feature flag doc to remove Cart and Checkout blocks + PaymentApi

Author: opr

docs/internal-developers/blocks/feature-flags-and-experimental-interfaces.md

@@ -33,32 +33,8 @@ The majority of our feature flagging is blocks, this is a list of them:
 
 ### Feature plugin flag
 
--   Cart block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/f76c7e46ce63d88059d8ce8b05d9409b78988e5f/assets/js/blocks/cart-checkout/cart/index.js#L51) | [PHP flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/4a1ee97eb97011458174e93e44a9b7ad2f10ca36/src/BlockTypesController.php#L177)).
--   Checkout block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/89b5d3032aa9d8b7368ba4edd3da222d076fbcaa/assets/js/blocks/cart-checkout/checkout/index.js#L86) | [PHP flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/4a1ee97eb97011458174e93e44a9b7ad2f10ca36/src/BlockTypesController.php#L176)).
--   Checkout Actions block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-actions-block/index.tsx#14)).
--   Checkout Billing Address block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-billing-address-block/index.tsx#14)).
--   Checkout Contact Information block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-contact-information-block/index.tsx#14)).
--   Checkout Express Payment block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/1cf7823eab9ccc974312fb806af7d8b77da8969e/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-express-payment-block/index.tsx#12)).
--   Checkout Fields block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-fields-block/index.tsx#13)).
--   Checkout Order Note block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/1cf7823eab9ccc974312fb806af7d8b77da8969e/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-order-note-block/index.tsx#13)).
--   Checkout Order Summary block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-order-summary-block/index.tsx#14)).
--   Checkout Payment block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-payment-block/index.tsx#14)).
--   Checkout Shipping Address block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-shipping-address-block/index.tsx#14)).
--   Checkout Shipping Methods block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-shipping-methods-block/index.tsx#14)).
--   Checkout Terms block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/89b5d3032aa9d8b7368ba4edd3da222d076fbcaa/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-terms-block/index.tsx#13)).
--   Checkout Totals block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/78e2de7a3ddfd3a554273fd6c2ff68478e9692ad/assets/js/blocks/cart-checkout/checkout-i2/inner-blocks/checkout-totals-block/index.tsx#L13)).
-
 ### Experimental flag
 
--   Cart block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/index.js#L44) | [PHP flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/961c0c476d4228a218859c658c42f9b6eebfdec4/src/BlockTypesController.php#L182)).
--   Cart Express Checkout block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/cart-express-payment-block/index.tsx#L13)).
--   Cart Items block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/cart-items-block/index.tsx#L13)).
--   Cart Line Items block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/cart-line-items-block/index.tsx#L13)).
--   Cart Order Summary block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/cart-order-summary-block/index.tsx#L14)).
--   Cart Totals block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/cart-totals-block/index.tsx#L13)).
--   Empty Cart block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/empty-cart-block/index.tsx#L13)).
--   Filled Cart block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/filled-cart-block/index.tsx#L13)).
--   Cart Proceed to checkout block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8516e87bddee6c07a080c934f3d8cc0683adef06/assets/js/blocks/cart-checkout/cart-i2/inner-blocks/proceed-to-checkout-block/index.tsx#L14)).
 -   Single Product block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/9b76ea7a1680e68cc20bfee01078e43ccfc996bd/assets/js/blocks/single-product/index.js#L43) | [PHP flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/4a1ee97eb97011458174e93e44a9b7ad2f10ca36/src/BlockTypesController.php#L181) | [webpack flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/341be1f56071fbd4b5ff975e8788d65a09512df2/bin/webpack-entries.js#L57-L59)).
 -   ⚛️ Add to cart ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/add-to-cart/index.js#L29-L32)).
 -   ⚛️ Product category list ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/category-list/index.js#L29-L32)).
@@ -72,16 +48,9 @@ We also have individual features or code blocks behind a feature flag, this is a
 
 ### Feature plugin flag
 
--   Payment API ([PHP flag 1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/07387889ec3a03769eb490821ee608d4e741e942/src/Domain/Bootstrap.php#L92-L94) | [PHP flag 2](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/07387889ec3a03769eb490821ee608d4e741e942/src/Domain/Bootstrap.php#L245-L254)).
 -   ⚛️ Product Price new controls ([JS flag 1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/price/attributes.js#L13-L44) | [JS flag 2-1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8d2f0ad8ade2c7217769b431f93de76d6cfacf6e/assets/js/atomic/blocks/product-elements/price/block.js#L116) | [JS flag 2-2](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8d2f0ad8ade2c7217769b431f93de76d6cfacf6e/assets/js/atomic/blocks/product-elements/price/block.js#L114) | [JS flag 2-3](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8d2f0ad8ade2c7217769b431f93de76d6cfacf6e/assets/js/atomic/blocks/product-elements/price/block.js#L91) | [JS flag 2-4](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8d2f0ad8ade2c7217769b431f93de76d6cfacf6e/assets/js/atomic/blocks/product-elements/price/block.js#L95) | [JS flag 2-5](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/8d2f0ad8ade2c7217769b431f93de76d6cfacf6e/assets/js/atomic/blocks/product-elements/price/block.js#L106) | [JS flag 3-1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/price/edit.js#L59-L108) | [JS flag 3-2](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/price/edit.js#L114-L131)).
 -   ⚛️ Product Title new controls ([JS flag 1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/attributes.js#L21-L40) | [JS flag 2-1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/block.js#L70-L72) | [JS flag 2-2](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/block.js#L94-L95) | [JS flag 2-3](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/block.js#L104) | [JS flag 3-1](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/edit.js#L47-L54) | [JS flag 3-2](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/edit.js#L77-L107) | [JS flag 3-3](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/b3a9753d8b7dae18b36025d09fbff835b8365de0/assets/js/atomic/blocks/product-elements/title/edit.js#L116-L129)).
 -   Utility function to pass styles to a block ([JS flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/9ebddbc5d21eb3cc67fedddbccbd86453313eb64/assets/js/atomic/utils/block-styling.js#L6-L12)).
--   Feature to create an account from the Checkout block ([PHP flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/4cedb65367be0d1c4c1f9dd9c016e3b1325cf92e/src/Domain/Services/CreateAccount.php#L40)).
--   Checkout package ([PHP Flag](https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/6da64165025e7a2afc1782e4b278d72536e7b754/src/AssetsController.php#L62-L64)) which contains:
-    -   SlotFills used in Cart and Checkout.
-    -   Checkout Filters.
-    -   Inner Blocks registry for Cart & Checkout i2.
-    -   Components exposed to 3PD.
 
 ### Experimental plugin flag