Internationalization pages

Hello!

I'd like to translate these pages into Russian:
https://www.w3.org/International/tutorials/language-decl/index
https://www.w3.org/International/questions/qa-html-language-declarations
https://www.w3.org/International/articles/language-tags/index
https://www.w3.org/International/questions/qa-choosing-language-tags
https://www.w3.org/International/questions/qa-lang-priorities

So according the Translation instructions I'm writing you to make sure that
these files are not currently being translated by someone else, and that it
isn't about to be updated.

Regards,
Dmitry Kuznetsov

mrbinwin@gmail.com