Adding multi-language support

[flarens]

Have tried many GUIs for yt-dlp and yours seems to be the most advanced. Thanks for the work you have done! Since the shell is used by people from different countries, it would be convenient to add the ability to translate the interface. For example, it would be enough to add to the program folder a language_en.ini file containing all interface lines in English. And people could edit it themselves for their native language. You wouldn't be required to do all these translations, but it would add considerable convenience for users who want to adapt the program to themselves.