How often are new languages added? Many people from Kazakhstan would like to add a translation of the manga in Kazakh. The choice fell on mangadex, as there are no other analogues.
As Kazakh isn't a language supported at moment, you can do something like this: select "other" language, and on the chapter name, you can write "name (қазақша)" (sorry, I have no idea which writing system is used on Kazakh officially).