Add type annotations

[tyoeer]

Type annotations improve the IDE experience, and sumneko's LSP allows exporting of information through --doc.

• In order to find constructors that need specifying, remove the vararg/... in the type boilerplate in main.lua
• Subtypes don't work well with the current way of specifying :new()

[tyoeer]

Class: all classes have been annotated as such, and have their supers set
New: the constructor has been provided types, and subtypes have been defined/annotated.
Desc: Class has a description
Methods: Methods have types (and description where relevant)

• ui/
  • base/
    • class
    • new
    • desc
    • methods
  • widgets/
    • class
    • new
    • desc
    • methods
  • layout/
    • class
    • new WIP
    • desc
    • methods
  • tools/
    • class
    • new
    • desc
    • methods
• levelhead/
  • campaign/
    • class WIP
    • new WIP
    • desc
    • methods
  • data/
    • class WIP
    • new WIP
    • desc
    • methods
  • level/
    • class
    • new
    • desc
    • methods
  • lhs/
    • class
    • new
    • desc
    • methods
  • The rest
    • class WIP
    • new WIP
    • desc
    • methods
• tools/
  • class
  • new
  • desc
  • methods
• chaoshead/
  • class WIP
  • new
  • desc
  • methods
• Other stuff