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/

doc/stub/fs.lua

@@ -0,0 +1,42 @@
+---  The FS API allows you to manipulate files and the filesystem.
+--
+-- @module fs
+
+function list(path) end
+function combine(base, child) end
+function getName(path) end
+function getSize(path) end
+function exists(path) end
+function isDir(path) end
+function isReadOnly(path) end
+function makeDir(path) end
+function move(from, to) end
+function copy(from, to) end
+function delete(path) end
+function open(path, mode) end
+function getDrive(path) end
+function getFreeSpace(path) end
+function find(pattern) end
+function getDir(path) end
+
+--- A file handle which can be read from.
+--
+-- @type ReadHandle
+-- @see fs.open
+local ReadHandle = {}
+function ReadHandle.read(count) end
+function ReadHandle.readAll() end
+function ReadHandle.readLine(with_trailing) end
+function ReadHandle.seek(whence, offset) end
+function ReadHandle.close() end
+
+--- A file handle which can be written to.
+--
+-- @type WriteHandle
+-- @see fs.open
+local WriteHandle = {}
+function WriteHandle.write(text) end
+function WriteHandle.writeLine(text) end
+function WriteHandle.flush(text) end
+function WriteHandle.seek(whence, offset) end
+function WriteHandle.close() end