Basic SASS infrastructure #127
Use the correct extension
Merge branch 'master' of https://github.com/StylishThemes/GitHub-Dark

* 'master' of https://github.com/StylishThemes/GitHub-Dark:
  RSS feed: add styling. Fixes #130
  Collaboration settings page styling
  Pull request creation page: Fix border
  Trending Repos: Fix owner name color
  Showcases: Fix sidebar border
  Re-add 128x128 spinner image
  version bump
  Add code tab-size styling
  Explore page: Fix showcase, #128
  Diff view: Fix file box background
Add background color to hide extraneous line

Closes #136
Merge pull request #137 from Poorchop/136

Add background color to hide extraneous line
Merge branch 'master' of https://github.com/StylishThemes/GitHub-Dark

* 'master' of https://github.com/StylishThemes/GitHub-Dark: (29 commits)
  Add background color to hide extraneous line
  version bump
  Followers: Fix name color
  Issues: Restore navigation focus background
  Notifications: Fix header color
  remove trailing comma. Fixes #134
  Issues: Another fix to sidebar hovers
  Issues: Fix label hover
  Repo sidebar: Fix selected item color
  Issues: Tweak travis icon
  Issues: Color picker and filter tweaks
  Discussions: Slightly brighter comment label border
  Prose diffs: Update styling, fixes #132
  Match color to .enterprise .dashboard-notice
  Fix dashboard-notice text color
  :joy: :yum: :heart_eyes: Emoji alignment
  Traffic stats: Fix border, Commit: Fix modified icon
  Discussions: Fix comment action icon hover
  Discussions: Fix current user highlight once more.
  fix discussion icons: closed, reopened & merged
  ...
Discussions: Fix white border between items
Discussions: Remove notification box background
Discussions: Fix info boxes below comment box
Add CONTRIBUTING.md file. Fixes #135
fix contributing links