docs: server-only/client-only in Next.js (#80408)

Closes:
https://linear.app/vercel/issue/DOC-4679/server-only-client-only-as-managed-by-nextjs
Fixes: #71071

Author: icyJoseph

docs/01-app/01-getting-started/08-server-and-client-components.mdx

@@ -507,7 +507,7 @@ export default function Page() {
 
 ### Preventing environment poisoning
 
-JavaScript modules can be shared between both Server and Client Components modules. This means it's possible to accidentanlly import server-only code into the client. For example, consider the following function:
+JavaScript modules can be shared between both Server and Client Components modules. This means it's possible to accidentally import server-only code into the client. For example, consider the following function:
 
 ```ts filename="lib/data.ts" switcher
 export async function getData() {
@@ -541,10 +541,6 @@ As a result, even though `getData()` can be imported and executed on the client,
 
 To prevent accidental usage in Client Components, you can use the [`server-only` package](https://www.npmjs.com/package/server-only).
 
-```bash filename="Terminal"
-npm install server-only
-```
-
 Then, import the package into a file that contains server-only code:
 
 ```js filename="lib/data.js"
@@ -563,4 +559,26 @@ export async function getData() {
 
 Now, if you try to import the module into a Client Component, there will be a build-time error.
 
-> **Good to know**: The corresponding [`client-only` package](https://www.npmjs.com/package/client-only) can be used to mark modules that contain client-only logic like code that accesses the `window` object.
+The corresponding [`client-only` package](https://www.npmjs.com/package/client-only) can be used to mark modules that contain client-only logic like code that accesses the `window` object.
+
+In Next.js, installing `server-only` or `client-only` is **optional**. However, if your linting rules flag extraneous dependencies, you may install them to avoid issues.
+
+```bash package="npm"
+npm install server-only
+```
+
+```bash package="yarn"
+yarn add server-only
+```
+
+```bash package="pnpm"
+pnpm add server-only
+```
+
+```bash package="bun"
+bun add server-only
+```
+
+Next.js handles `server-only` and `client-only` imports internally to provide clearer error messages when a module is used in the wrong environment. The contents of these packages from NPM are not used by Next.js.
+
+Next.js also provides its own type declarations for `server-only` and `client-only`, for TypeScript configurations where [`noUncheckedSideEffectImports`](https://www.typescriptlang.org/tsconfig/#noUncheckedSideEffectImports) is active.