chore: minor improvement for docs

contracts/message/framework/MessageReceiverApp.sol

@@ -13,7 +13,7 @@ abstract contract MessageReceiverApp is IMessageReceiverApp, MessageBusAddress {
     }
 
     // Add abort prefix in the reason string for require or revert.
-    // This will abort (revert) the message execution without markig it as failed state,
+    // This will abort (revert) the message execution without marking it as failed state,
     // making it possible to retry later.
     function _abortReason(string memory reason) internal pure returns (string memory) {
         return MsgDataTypes.abortReason(reason);

contracts/message/libraries/MsgDataTypes.sol

@@ -6,7 +6,7 @@ library MsgDataTypes {
     string constant ABORT_PREFIX = "MSG::ABORT:";
 
     // Add abort prefix in the reason string for require or revert.
-    // This will abort (revert) the message execution without markig it as failed state,
+    // This will abort (revert) the message execution without marking it as failed state,
     // making it possible to retry later.
     function abortReason(string memory reason) internal pure returns (string memory) {
         return string.concat(MsgDataTypes.ABORT_PREFIX, reason);

contracts/message/messagebus/MessageBusSender.sol

@@ -128,7 +128,7 @@ contract MessageBusSender is Ownable {
     /**
      * @notice Calculates the required fee for the message.
      * @param _message Arbitrary message bytes to be decoded by the destination app contract.
-     @ @return The required fee.
+     * @return The required fee.
      */
     function calcFee(bytes calldata _message) public view returns (uint256) {
         return feeBase + _message.length * feePerByte;