Indicator of http server readiness

[GrandyB]

It's currently not obvious that you need to do an 'update' loop before things become available - it needs to read the data from the google sheet before saving anything or the webserver being able to serve anything.

Need to either:
A) Add some visual indicator that the http server is not active pre-hitting update
B) Auto update once config is chosen
C) B + do this when loading the "last used config" at startup

Might actually prefer C; thoughts?