Upgrade guide to website

Includes fully updated content
Fixes #8
Fixes #11
Fixes #16
Fixes #20
Add custom icons
Fix README
Improve sidebar

Decrease h1 font-size
Fix nav link order
Make some room
Fix #13
Fix #21: Correct link to license
Merge pull request #22 from juthilo/master

Merge master
Follow-up to
Update versions
Update Rouge version
fixed broken links