Reimplement site search with Fusejs

[ninjamuffin99]

With Fuse.js, we can add a site search that properly indexes all the site's content (during build time) that can be accessed anywhere on the site with much richer results than previous site search implementation (loading google with "[search term] site:haxeflixel.com"

https://www.fusejs.io/

Core

to be written...

Polish

• A nice modal / popover the current content when site searching?
• using something like / to initiate the search (or ctrl-f ?)