The RBTools documentation has a lot of good information, but not all of

it is easy to find. While fixing this is a longer project, this change

takes a baby step by cleaning up parts of the front page, extracting

links formerly in paragraphs and making them stand out more as

individual items.
This is basically what we did a while back for the main Review Board

documentation. Several of the more important pages to point out are now

shown right on the front page, much more clearly than before. In

particular, the full commands list has been placed on the front page,

and the configuration information has been broken up better.
This should help people more easily find what they're looking for.

Built the docs. Checked for build errors, bad links, and spelling errors.