Add Lua bindings

[paulstraw]

Is your feature request related to a problem? Please describe.
I would like for this project to have a nice Lua interface.

Describe the solution you'd like
First, this will need additional procs for complex types in the Nim/C bindings: https://github.com/samdze/playdate-nim/blob/main/src/playdate/lua.nim

Once that exists,

Describe alternatives you've considered
One alternative would be to expose a simpler API. This would require a bunch of gross globals and a breaking change down the road, though.

Additional context
N/A