First release of Alpenglow

Improvements over Afterglow:

• Support for bold and italics in LaTeX, Markdown, ... (@vikjam)
• GitGutter support in Monokai & Twilight color schemes (@vikjam)
• Improved README.md
• Add/fix icons for:
  • Elixir (@vikjam)
  • Grunt (@mknabe)
  • Gulp (@mknabe)
  • Julia (@vikjam)
  • MATLAB (@egeerardyn)
  • Perl (@nugged)
  • PHP (@vikjam)
  • R (@vikjam)
  • Rails (@vikjam)
  • Stata (@vikjam)