chore: add some natspec

Author: prestwich

src/apps/Lido.sol

@@ -13,16 +13,29 @@ import {BurnMintERC20} from "../vendor/BurnMintERC20.sol";
 /// Allows bridging two ways:
 /// - Signet native bridging with Orders.
 /// - CCIP Teleporting via support for the CCT standard.
+///
+/// Bridging with Signet:
+/// - bridgeIn: Creates an order that delilvers wstETH to `HOST_PASSAGE` on L1.
+///   If the order is filled, mints stETH on L2 to `recipient`.
+/// - bridgeOut: Burns stETH on L2 from `msg.sender`, and creates an order
+///   that delivers wstETH to `recipient` on L1.
+/// - enter: Transfers WETH from `funder`, creates an order that converts
+///   WETH to wstETH on L1 and delivers it to `HOST_PASSAGE`, and mints stETH
+///   on L2 to `recipient`.
+///
 contract LidoL2 is SignetL2, BurnMintERC20 {
     using SafeERC20 for IERC20;
 
+/// @notice The WstETH token on the host.
     address public immutable HOST_WSTETH;
 
     constructor(address _hostWsteth) BurnMintERC20("Signet Lido Staked Ether", "stETH", 18, 0, 0) {
         HOST_WSTETH = _hostWsteth;
         WETH.forceApprove(address(ORDERS), type(uint256).max);
     }
 
+    /// @notice Create an order to bridge in wstETH from L1, and mint stETH on
+    /// L2.
     function _bridgeIn(address recipient, uint256 amount, RollupOrders.Input[] memory inputs) internal {
         RollupOrders.Output[] memory outputs = new RollupOrders.Output[](1);
         outputs[0] = makeHostOutput(HOST_WSTETH, amount, address(HOST_PASSAGE));
@@ -32,10 +45,16 @@ contract LidoL2 is SignetL2, BurnMintERC20 {
         _mint(recipient, amount);
     }
 
+    /// @notice Bridge in wstETH from L1, and mint stETH on L2.
     function bridgeIn(address recipient, uint256 amount) external {
         _bridgeIn(recipient, amount, new RollupOrders.Input[](0));
     }
 
+    /// @notice Burn stETH on L2, and create an order to bridge out wstETH to
+    /// L1. If the order is not filled, the stETH will not be burned.
+    ///
+    /// This transaction should be paired with some off-chain logic that fills
+    /// orders from the L1 bank.
     function bridgeOut(address recipient, uint256 amount) public {
         _burn(msg.sender, amount);
 
@@ -45,6 +64,8 @@ contract LidoL2 is SignetL2, BurnMintERC20 {
         ORDERS.initiate(block.timestamp, new RollupOrders.Input[](0), outputs);
     }
 
+    /// @notice Transfer WETH from `funder`, create an order to convert it to
+    /// wstETH on L1 and bridge it to L2, and mint stETH to `recipient`.
     function enter(address funder, uint256 amountIn, address recipient, uint256 amountOut) external {
         WETH.safeTransferFrom(funder, address(this), amountIn);