External option documentation

[Procyonae]

Summary

None

Purpose of change

External options aren't even mentioned in documentation
Loading comments and storing them twice is very dumb

Describe the solution

Renames game_balance.json to external_options.json bc most of them have nothing to do with game balance, all the external options randomly just got lumped into it at some point.
Adds simple documentation mainly pointing modders to /core/external_options.json
Changes the "info" comments to "//" comments and removes dupes in mods as they're unlikely to remain up to date

Describe alternatives you've considered

Make a table of id(name), type, default and a description of each external option rather than having the comments in the dda file but that felt redundant with how simple the type currently is, the file is pretty much already a table that doesn't need maintaining separately.

Testing

Game compiles and loads

Additional context