riot.im website l10n

[532910]

Please make https://riot.im website localized:

1. it should use Accept-Language HTTP header. (Like debian.org does, for example.)
2. and take translation from translate.riom.im

[turt2live]

Duplicate of #4458

[532910]

sorry

[turt2live]

no worries, we'd rather have duplicates than silence. I just have to sound a bit cold in my message to make github do the right thing is all :)