An initial stab at documentation generation (#360)

This adds documentation comments to many of CC's Lua APIs, and
a couple of the Java ones, through the use of stubs. We then
export these to HTML using illuaminate [1] and upload them to our
documentation site [2].

Uploads currently occur on pushes to master and any release/tag. The
site is entirely static - there is no way to switch between versions,
etc... but hopefully we can improve this in the future.

[1]: github.com/SquidDev/illuaminate/
[2]: https://tweaked.cc/

src/main/resources/assets/computercraft/lua/bios.lua

@@ -21,7 +21,7 @@ if _VERSION == "Lua 5.1" then
     local nativeloadstring = loadstring
     local nativesetfenv = setfenv
 
-    --- Historically load/loadstring would handle the chunk name as if it has
+    -- Historically load/loadstring would handle the chunk name as if it has
     -- been prefixed with "=". We emulate that behaviour here.
     local function prefix(chunkname)
         if type(chunkname) ~= "string" then return chunkname end