doc: add some explanation on scale

Author: 0xtekgrinder

contracts/helpers/GenericHarvester.sol

@@ -257,6 +257,8 @@ contract GenericHarvester is BaseHarvester, IERC3156FlashBorrower, RouterSwapper
     /// some yieldBearingAsset that can then be used for people looking to burn stablecoins
     /// @dev Due to potential transaction fees within the Transmuter, this function doesn't exactly bring
     /// `yieldBearingAsset` to the target exposure
+    /// @dev scale is a number between 0 and 1e9 that represents the proportion of the 
+    /// it is used to lower the amount of the asset to harvest for exemple to have a lower slippage
     function harvest(address yieldBearingAsset, uint256 scale, bytes calldata extraData) public virtual {
         if (scale > 1e9) revert InvalidParam();
         YieldBearingParams memory yieldBearingInfo = yieldBearingData[yieldBearingAsset];