update documentation

docs/lib/utils/SafeTransferLib.md

@@ -1,7 +1,62 @@
-# SafeTransferLib
+# Solidity API
 
-_Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/SafeTransferLib.sol)_
+## SafeTransferLib
 
 Safe ETH and ERC20 transfer library that gracefully handles missing return values.
 
-_Caution! This library won't check that a token has code, responsibility is delegated to the caller._
+_Caution! This library won't check that a token has code, responsibility is delegated to the caller._
+
+### ETHTransferFailed
+
+```solidity
+error ETHTransferFailed()
+```
+
+_The ETH transfer has failed._
+
+### TransferFromFailed
+
+```solidity
+error TransferFromFailed()
+```
+
+_The ERC20 `transferFrom` has failed._
+
+### TransferFailed
+
+```solidity
+error TransferFailed()
+```
+
+_The ERC20 `transfer` has failed._
+
+### safeTransferETH
+
+```solidity
+function safeTransferETH(address to, uint256 amount) internal
+```
+
+_Sends `amount` (in wei) ETH to `to`.
+Reverts upon failure._
+
+### safeTransferFrom
+
+```solidity
+function safeTransferFrom(contract ERC20 token, address from, address to, uint256 amount) internal
+```
+
+_Sends `amount` of ERC20 `token` from `from` to `to`.
+Reverts upon failure.
+
+The `from` account must have at least `amount` approved for
+the current contract to manage._
+
+### safeTransfer
+
+```solidity
+function safeTransfer(contract ERC20 token, address to, uint256 amount) internal
+```
+
+_Sends `amount` of ERC20 `token` from the current contract to `to`.
+Reverts upon failure._
+