message: update watch API
diff: @@ -7,12 +7,7 @@ export default function ApiWatch({ tabIndex }: any) {
  return (
  <>
  <CodeHeading>
  - <h2>
  - watch:{" "}
  - <Type>
  - (string | string[] | undefined) => {`{ [key:string] : any }`}
  - </Type>
  - </h2>
  + <h2>watch</h2>
  </CodeHeading>
  <p>This will watch specified input/inputs and return its value.</p>
  <ul>
  @@ -67,7 +62,7 @@ export default function ApiWatch({ tabIndex }: any) {
  <code>watch('inputName', 'value')</code>
  </td>
  <td>
  - <Type>{`string | string[] | { [key:string] : any }`}</Type>
  + <Type>{`string | string[] | { [key:string] : any } | undefined`}</Type>
  </td>
  </tr>
  <tr>
  