message: docs(masthead-search): fix wrong event name in the doc
  ### Changelog
  **Changes**
  Fix wrong doc for custom search box implementation, where `dds-masthead-search-input` event name instead of `input` should be used.
diff: @@ -180,8 +180,8 @@ import '@carbon/ibmdotcom-web-components/es/components/masthead/masthead-search-
  The search box appears when user clicks on the magnifier icon.
  The search box disappears when user clicks on the X button.
  -Fires an `input` event when user types in a search query string.
  -Application code should take care of fulfilling the search result upon `input` event, by putting `<dds-masthead-search-item text="The search result">` as the child elements of `<dds-masthead-search>`. Here's an exmaple:
  +Fires an `dds-masthead-search-input` event when user types in a search query string.
  +Application code should take care of fulfilling the search result upon `dds-masthead-search-input` event, by putting `<dds-masthead-search-item text="The search result">` as the child elements of `<dds-masthead-search>`. Here's an exmaple:
  ```javascript
  import throttle from 'lodash-es/throttle';
  