* Add jekyll-toc include
* Reduce whitespace generated by comments
* Add table of contents include to `single` layout
* Replace `toc` include with jekyll-toc enabled YAML Front Matter
* Update README
* Update table of contents documentation
- Revise `toc` helper include to mention that it will be deprecated in the next major version.
- Add documentation to `single` layout explaining how to enable table of contents on those pages.
* Update CHANGELOG and history
* Update LICENSE
Close#1222
* Add YIQ Color Contrast mixin
* Remove text underline from `.btn` links
* Move YIQ variables
* Simplify button classes using YIQ color contrast mixin
- DRY up button CSS using Sass list and YIQ color contrast mixin.
- Move `color` and `background-color` to new `btn--primary` class instead of assinging on the default class. Removes the need to override them.
* Add `.btn--primary` to buttons that just had `.btn`
* Apply changes to `/docs`
* Add `.btn--primary` class
* Update CHANGELOG and history
* Add sample form
* Abstract colors away into Sass variables for easier themeing
* Add "dark" skin
* Replace hardcoded color with SCSS variable
* Invert Font Awesome icons' colors in author sidebar and footer
* Add Sass changes to `/docs`
* Use primary button type instead of inverse
* Add missing `!default` on `$muted-text-color`
* Add `contrast` and `sunrise` skin colors
* Add `dirt` skin color
* Add `air` skin color option
* Add `mint` skin color
* Add `btn--primary` class to Submit Comment button
* Set skin to `default`
* Document skin color options
* Add note about skin SCSS import
Close#1208
