docs: update cosigner info comments (#306)

src/reactors/V3DutchOrderReactor.sol

@@ -14,7 +14,7 @@ import {Math} from "openzeppelin-contracts/utils/math/Math.sol";
 import {CosignerLib} from "../lib/CosignerLib.sol";
 
 /// @notice Reactor for V3 dutch orders
-/// @dev V3 orders must be cosigned by the specified cosigner to override starting block and value
+/// @dev V3 orders must be cosigned by the specified cosigner to set the starting block and override the value
 /// @dev resolution behavior:
 /// - If cosignature is invalid or not from specified cosigner, revert
 /// - If inputAmount is 0, then use baseInput
@@ -127,7 +127,7 @@ contract V3DutchOrderReactor is BaseReactor {
 
     /// @notice validate the dutch order fields
     /// - deadline must have not passed
-    /// - cosigner is valid if specified
+    /// - cosigner must always be provided and sign the cosignerData
     /// @dev Throws if the order is invalid
     function _validateOrder(bytes32 orderHash, V3DutchOrder memory order) internal view {
         if (order.info.deadline < block.timestamp) {