Made the theme button toggable by keyboard
Added aria-label to many <a> without any text (usually, they contains Font Awesome icons)
Added aria-hidden whenever necessary
Labelled the "Copy URL and Description" contained in footer
Added an hidden label for the menu toggle for mobile accessibility
Changed some colors to meet the Color Contrast AA level: https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html
* Move all images to assets/img
* Move all scripts to assets/js
* Move all webfonts to assets/webfonts
* Move all files to assets/files
* Move css to assets/css and add imports
* Adjust all references to assets folder
* Fix tor icon path
* Rewrite custom css to sass and add variables
* Change ?v on style.css to 5.
* Enable Sass minification
* Remove CryptoPaper-full.7z