Rename "fonts" to "misc"
Downgrade headings in reveal.js.md
Add fallback fonts in CSS
Drop superfluous blank lines

These extra empty lines would mess up the slide structure
Move all shellinabox content into Markdown
Move all qrcode.js content into Markdown
Move all GitHub content into Markdown
Add opening QR code
Merge branch 'master' into gh-pages
Revert "Add opening QR code" (gh-pages branch only)

This reverts commit e9f698a99fb05f9cbe52ce6c378fd6b33a6c0fb2.