fix dependencies, fix styles, improve Rake tasks

- switch to awestruct HEAD
- update haml
- set markdown impl per ruby
- add asciidoctor
- use bundle exec in rake tasks
- add setup rake task
- fix bootstrap styles to match current website
- add missing bootstrap images
Merge pull request #30 from mojavelinux/style-and-build-edits

fix dependencies, fix styles, improve Rake tasks