[dasc] - Add a way or document how to set Metadata for the structured content page

[dasc] - In the form editor view, there isnt a way to set Metadata for the structured content page.

These structured pages when published, gets indexed and appear in query-index.json and sitemap.xml and there isnt an intuitive way to add properties like `robots | noindex, nofollow`

If we are not going to support this metadata properties in the form editor view, We should atleast document or add a link on https://docs.da.live/developers/guides/structured-content

**Workaround**
We can go into Edit mode or use Bulk Metadata sheet to set metadata for the page but that's not intuitive enough

Start with the structured content guide at https://docs.da.live/developers/guides/structured-content and inspect the form editor view, Edit mode, and Bulk Metadata sheet mentioned in the issue. Determine whether metadata such as robots=noindex,nofollow should be supported in the editor or documented with a link; done means the workflow is intuitive and the published page metadata is reflected as expected.

Written by the indexing model from the issue text.