NGWPC-11670 - Add Streamlit Dashboard Documentation

[brock-hinkson]

Add Streamlit Dashboard Documentation

Additions

• Markdown files that constitute a comprehensive 'user guide' for the streamlit dashboard
• Images that embed into the markdown files when rendered
• Extra logic that allows mkdocs to serve the new docs

[quercoak]

Generally looks good. See comments. Here's some other notes.

• If you spin up the API docs you should see the formatting issues.
• Please name the dashboard docs URI dashboard-docs . It's cleaner as dashboard but it might have collision issues with the fact that when deployed the uri is /dashboard for both the real dashboard and the dashboard docs. Part of this is that we should not have the docs just at the root of API, but that's just how it is.
• Please add a blurb on the dashboard to the main index.md. I have some edits coming to that but that will have it be there when I'm ready to make them.