Clean up docs after section captions added

[dhermes]

• Renaming some .rst docs since captions now hold headings.
• Removing the out-of-date, hard to find _components/*-quickstart.rst as well.
• Folded documentation for connections in client documentation, since we don't really ever need to talk about a connection without a client.
• Folding in getting started doc into main index.rst.
• Removing unused Makefile and components.

Fixes #1034.

[dhermes]

@tseaver Regarding all your "Ditto" comments about removed documents, none of those were published in any place.

We can follow this up with usage docs or on-ramps for each sub-package?

[tseaver]

Re the _components fragments: if we don't need anything like them anywhere, then just dropping them is fine. FWIW, I have a feeling that trying to review docs as diffs is waaaay harder than reviewing software.

[dhermes]

Maybe we should see how difficult it would be to use https://github.com/bslatkin/dpxdt for docs diffs?

[tseaver]

I'm less worried about how the changes look, and more about how hard it is to keep the overall context / usage paths straight in one's head, in order to make reasoned judgements about the changes.

[dhermes]

@tseaver To confirm, these are the things to do:

• Put Makefile back
• Make page titles that are ambiguous also refer to the package they live in

[tseaver]

@dhermes that sounds right to me.

[dhermes]

@tseaver PTAL

[tseaver]

LGTM