* AUDIO_LANGUAGES and TEXT_LANGUAGES are now validated against
supported languages
* Alternately, "all" can be specified to include all languages
(default for TEXT_LANGUAGES)
* Also fixed linker script not regenerating on language change
CMake builds now have parity with the Makefile (and more!)
* Comma-separated languages can be specified using the AUDIO_LANGUAGES
CMake cache variable (defaults to just English)
* Multi-language builds can include any combination of supported languages
* Single-language builds can use any supported language
As part of this, I refactored the sound lookup tables to not store
information about non-localized sounds (which previously occupied most
of the table).
I move contributing.md to the documentation folder.
I moved setup.sh to the tools folder.
I renamed contributing.md from all caps to lowercase to match other files.
I moved docker setup to it's own file.
I moved some instructions to the add_vpk_here.md file.
