Adds a multi-lingual version of the page, with the standard English
page being served at `/` and `/en`, and the new Russian version at
`/ru`.
Change-Id: I54ceea91d1442ee7b8717b59083e5d07c36ca8b0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7940
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
