~aleteoryx/lfm_embed

ref: adc1a486faf473eb7d993ca5df78485f0938d1d0 lfm_embed/src/theming d---------
Document lua, fix small theme bugs
Lua dev mode functional
Lua support feature-complete

Full implementation of debug mode still pending
lua loading
html.lua functional
Start of Lua support
Add SPDX info to all files
Theming refactor

Theming has been broken off into a seperate space, so that it'll be easier to add lua support later.