Web console: add a nice UI for overlord dynamic configs and improve the docs

[vogievetsky]

Add a nice form (with JSON fallback) to the overlord dynamic config dialog

To do this I had to read the docs and found them lacking. I asked @kfaraz to help me make heads and tails of the logic. Here was his summary that I rewrote in the docs.

Here are his original notes (screenshot form Slack DM):

If there are better way to word it I am all ears.

[317brian]

Thanks Vad! Mostly minor grammatical fixes. There were some remaining inconsistencies with categoryConfig and some other properties showing up in multiple forms: categoryConfig, CategoryConfig, and categoryConfig. They should all typically be like categoryConfig (literal name in code font). I think we caught them all between your fixes and my suggestions.

[kfaraz]

Thanks a lot for the changes, @vogievetsky. The document is much more pleasant to read now. The changes look good to me overall. I have just left some minor suggestions.

[kfaraz]

Tried out the new console changes, the Overlord config is very easy to use now!
Encountered a minor bug. The content in the suggestion box seems to overflow in some cases.