Improve documentation organization

[andrewdmontgomery]

Closes #

Description

Adds some organization to the Gravatar module's documentation.

Testing Steps

[andrewdmontgomery]

I saw that we were exporting Gravatar from GravatarUI, and this was allowing us to link symbol documentation in GravatarUI to various symbols in Gravatar.

But the downside of that approach is that the GravatarUI documentation then contains all of the Gravatar symbols, making it much harder to find and understand the symbols from GravatarUI.

So I've removed that export, and made adjustments to a few documentation entries in GravatarUI that were linking to Gravatar symbols (which won't work without exporting them in GravatarUI).

It's a trade-off:

• Links work, but GravatarUI and Gravatar documentation are both included – and completely unorganized – in the GravatarUI documentation
• Keep the documentation of the modules separate, but lose linking to Gravatar symbols from GravatarUI documentation.

There's another challenge with having all documentation in the GravatarUI module. The more formatting, images, etc. that we add to Gravatar documentation, the further it will drift from whatever gets automatically generated in the GravatarUI module. Put another way: if it is worth adding formating to the Gravatar module documentation, it is also worth adding that same formatting again to the Gravatar module documentation that is included with the GravatarUI module. That's twice the work. We could potentially automate some of it.