Update apps, stm wiki articles
Add figure template
Add Opusmodus screenshot
Add a shadow to figures
Add custom links, repo_url variable
Add some content to the footer
Add a sidebar to the wiki
Style the footer and fix figure style
Add cmacro, Softscan to apps.md
Add some text to books.md
Expand clos.md
Add a bunch of text and sections to the StumpWM article
Add implementations article
Add Buildapp article
Add 'All Pages' page
Add guide for contributors
Update wiki index