Documentation for Mantainance Dashboard

[laupalombi]

The new dashboard is here - we need some documentation explaining how it works.

[laupalombi]

hey @Brookke, do you mind contributing to the docs repo (https://github.com/home-assistant/home-assistant.io) explaining how this panel works, where it gets the info etc? I can review it (add me as reviewer) but it would be a lot better coming from you that build the feature.