Various documentation improvements.

Hope these are all ok. Let me know if you prefer a different approach on any of these changes.

 - Update badges to be on one line to take up less space.
 - Shorten URLs for badges.
 - Wrap all lines @ 80 chars.
 - Make capitalization consistent on titles.
 - Update and add links where appropriate.
 - Fix indentation and make it consistent (use spaces).
 - Add OJO repository references.
 - Various spelling / typo / grammar fixes.