Where can I find more information about the available fragment tags for the issue panel?

The Forge tutorial application creates an issue panel and defines it with these tags:

` <Fragment>
      <Text>Hello world!</Text>
      <Text>
        Number of comments on this issue: {comments.length}
      </Text>
  </Fragment>`

Where can I find out about other valid tags (such as input fields, buttons, etc.) that can be used in this fragment for the issue panel?

Looks like this is the place: https://developer.atlassian.com/platform/forge/ui-kit-components/