Various related string corrections in the gui/ files:
* Learn To Play → Learn to Play (articles, conjunctions, and prepositions are not capitalized in title case, unless it's the first word)
* Anti-Aliasing → [[ https://www.lexico.com/en/definition/antialiasing | antialiasing ]] (missed in D2437/rP23368)
* Control Group Membership → Control group membership (added in D2176/rP23476)
* setup (verb) → set up
* gamesetup → game setup
* gamesetting → game setting
* gamespeed → game speed