Add the lang folder to be able to add translations in the future. I wanted to translate the mod into languages such as Ukrainian and Russian, but I realized that there is no lang folder.

Adding the lang folder will not do anything, you need to add support for text localization in the code itself for each string displayed.
But yeah, it's cool to be able to translate the mod into our native languages.

I understand that simply adding the lang folder will not allow adding translations, but I didn't know how to explain it correctly. Thanks for the answer!

I could help with translating into German.

I could do the french Translation if needed when possible.