Add introduction tag for v5.1 contracts (#5228)

Co-authored-by: Ernesto García <ernestognw@gmail.com>

contracts/token/ERC20/extensions/ERC1363.sol

@@ -12,6 +12,8 @@ import {ERC1363Utils} from "../utils/ERC1363Utils.sol";
  * @dev Extension of {ERC20} tokens that adds support for code execution after transfers and approvals
  * on recipient contracts. Calls after transfers are enabled through the {ERC1363-transferAndCall} and
  * {ERC1363-transferFromAndCall} methods while calls after approvals can be made with {ERC1363-approveAndCall}
+ *
+ * _Available since v5.1._
  */
 abstract contract ERC1363 is ERC20, ERC165, IERC1363 {
     /**