Finalize sphinx documents and directory structure.

[rec]

First, pull up sphinx/source - this is a legacy of the default sphinx.

Then we need to fix sphinx/index.rst:

• Overall summary here - should be same as README.md.
• Links to different modules and submodules \ timedata's module should NOT have everything, just the "default items".
• Add links to other .md documents.

[rec]

Here's the document roadmap:

• 1 top level document.
• 1timedata module - automatically generated, links to all the models.
• For each color model, a timedata.$model module - automatically generated.
• Separate HTML documents for each .md document in the source.
• Generated source.

[rec]

We are only documenting one "struct" - Render3 - so that can go at the end of the top-level timedata document, which is otherwise small and a sort of "catchall".

The top level document should link right to ColorRGB and ColorListRGB quite close to the top, so people can get to "the meat" in one click from the top page.