Feat/reworked language codes (#865)

* Reworked language codes to use Steam localization standards

* Reworked language codes tweaks (#864)

* Language code rework tweaks

* Update bg.lua

* Reevaluate whether a language is WIP

* Update bg.lua

* Even better mark for languages as WIP (> 80% translated)

* Update zh_cn.lua

* Update cs.lua

* Fix for game language codes

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Co-authored-by: kittenchilly <mario.pikmin.zelda@gmail.com>

descriptions/rep/fr.lua

@@ -2,7 +2,7 @@
 -----  Basic French descriptions -----
 --------------------------------------
 
--- Last Sync with en_us: 08.08.2021
+-- Last Sync with English: 08.08.2021
 
 -- FORMAT: Item ID | Name| Description
 -- '#' = starts new line of text