Multilingual enhachment extension

[Terion]

I am not a PHP-developer (I know something, but not very much), so I have no possibility to make such extension, but it s very small and easy, and I think, that experiensed developer would make it in 15 minutes.

:idea: The idea is to make more flexible multilingual management.

Contao can automaticly change language depending on browser lang. But only one site lang to one browser lang.
But, for example:
— We have English, German and Russian langs.
It would be very good to redirect some group of langs to each site lang.
Dutch, Holland, German => de
Russian, Ukrainian, Belarussian, etc (most Slavic and Eastern Europe langs) => ru
Others (fallback) => en

Dutch and Hollands are easier (as I think) to read German.
Almoust all Eastern Europeans know Russian.
Etc.

Very tiny but very useful extension, and it would be very good, if someone make it.
Thank you.

PS
Sorry for not ideal English

[Terion]

BTW
I understand, that I can write php-code, that would manage this, and include it into the template or using insert tag.
But it is not "contao-way", I think. It wouldn't be editable in BE and make some problems in adding new langs.
Developers, for their own sites, or sites that are meneged by them, can do so, but it is not good for customer-sites...