Fix lists, links in Bootstrap theme README [ci skip]

- Sub-lists need indent to properly show on README render
- Update the heading numbers to match TOC
- Updates links to Bootstrap after they moved from Twitter
- List under Views section should only list two items,
  move the other bullets out into separate Exceptions list
Merge pull request #245 from randomecho/copyedit-readme-bootstrap

Fix lists, links in Bootstrap theme README [ci skip]