Update documentation structure

[choldgraf]

In communicating with a potential community who wishes to use our hub, I was pointing them to the pilot documentation and found that it was a bit hard to navigate, given that there was some information that was split across multiple pages, and some section titles that didn't quite seem right.

This is an attempt at refactoring the structure of this documentation a bit so that it has the following properties:

• Fewer top-level sections for people to pick between
• Top-level sections are grouped by "Topic" and sections underneath are either of a "how to" variety or "explanatory" variety
• Three top level sections: "About", "Get started", "Topic Guides"

I've also added a page on creating a new hub that we can point people to.

Other than that the content shouldn't be changed.

[choldgraf]

@yuvipanda would love your thoughts on this - I know that the original structure of this website was written with diataxis.fr in mind - I think that this is still within the spirit of that guide (I've seen many other projects use "Topic Guides" as a high level organizing structure...I've found this to be a more intuitive high-level grouping of sections that prevents the landing page from having a gigantic list of links). WDYT?

[choldgraf]

Seeing if @GeorgianaElena would be willing to take a look as well as she is great w/ docs :-)

[choldgraf]

ok, comments from @GeorgianaElena resolved...I'll merge this in since we've got an approval, and I'm happy to iterate further on the documentation if folks have more thoughts.

thanks @GeorgianaElena for the review :-)

[damianavila]

OK, I little bit late here but a quick overview feels nice to me as well 😉 .