FLUID-5451: Polish and cleanup of markup
- Removed unused CSS from docpad.coffee
- restructured Community links to use icons.
- general clean-up of CSS
- added feedback tool to showcase
- added aria-labelledby to Sections
- added presentation roles to icons
- added community links icon font
FLUID-5451: Cleaned up fonts
- Added readme for icon fonts
- Removed unecessary font demo files.