Add more docs

Author: Dominator008

contracts/Bridge.sol

@@ -7,6 +7,9 @@ import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import "./libraries/PbBridge.sol";
 import "./Pool.sol";
 
+/**
+ * @title The liquidity-pool based bridge.
+ */
 contract Bridge is Pool {
     using SafeERC20 for IERC20;
 

contracts/FarmingRewards.sol

@@ -9,6 +9,9 @@ import "./interfaces/ISigsVerifier.sol";
 import "./libraries/PbFarming.sol";
 import "./safeguard/Pauser.sol";
 
+/**
+ * @title A contract to hold and distribute farming rewards.
+ */
 contract FarmingRewards is Pauser {
     using SafeERC20 for IERC20;
 

contracts/Pool.sol

@@ -12,9 +12,9 @@ import "./safeguard/VolumeControl.sol";
 import "./safeguard/DelayedTransfer.sol";
 import "./Signers.sol";
 
-// add liquidity and withdraw
-// withdraw can be used by user or liquidity provider
-
+/**
+ * @title Liquidity pool functions for {Bridge}.
+ */
 contract Pool is Signers, ReentrancyGuard, Pauser, VolumeControl, DelayedTransfer {
     using SafeERC20 for IERC20;
 

contracts/Signers.sol

@@ -6,6 +6,9 @@ import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
 import "@openzeppelin/contracts/access/Ownable.sol";
 import "./interfaces/ISigsVerifier.sol";
 
+/**
+ * @title Multi-sig verification and management functions for {Bridge}.
+ */
 contract Signers is Ownable, ISigsVerifier {
     using ECDSA for bytes32;
 

contracts/StakingReward.sol

@@ -8,6 +8,9 @@ import {DataTypes as dt} from "./libraries/DataTypes.sol";
 import "./safeguard/Pauser.sol";
 import "./Staking.sol";
 
+/**
+ * @title A contract to hold and distribute CELR staking rewards.
+ */
 contract StakingReward is Pauser {
     using SafeERC20 for IERC20;
 

contracts/WithdrawInbox.sol

@@ -4,6 +4,9 @@ pragma solidity 0.8.9;
 
 import "./safeguard/Ownable.sol";
 
+/**
+ * @title A contract to initiate withdrawal requests for contracts tha provide liquidity to {Bridge}.
+ */
 contract WithdrawInbox is Ownable {
     // min allowed max slippage uint32 value is slippage * 1M, eg. 0.5% -> 5000
     uint32 public minimalMaxSlippage;