docs: add comments on safety checks

Author: MerlinEgalite

src/libraries/ChainlinkDataFeedLib.sol

@@ -12,6 +12,15 @@ import {ErrorsLib} from "./ErrorsLib.sol";
 library ChainlinkDataFeedLib {
     /// @dev Performs safety checks and returns the latest price of a `feed`.
     /// @dev When `feed` is the address zero, returns 1.
+    /// @dev Notes on safety checks:
+    /// - A stale period is not checked since the heartbeat of a Chainlink feed is an offchain parameter that can
+    /// change any time and checking the price deviation onchain is not possible. It was not recommended by the Chailink
+    /// team either.
+    /// - The price is not checked to be in the min/max bounds since the check is already performed by Chainlink most of
+    /// the time. Adding
+    /// a safety margin would be arbitrary as well since the contract is immutable.
+    /// - No fallback is used. In case the oracle reverts, Morpho Blue users can still exit their positions but
+    /// can't be liquidated.
     function getPrice(AggregatorV3Interface feed) internal view returns (uint256) {
         if (address(feed) == address(0)) return 1;