Add Russian Language

[sspencerwire]

• We have received a requestt to translate the documentation in Russian
• this change would add the Russian language to the mkdocs.yml file
• I've tested this configuration locally and it appears to work as expected

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Name	Status	Preview	Updated
rockylinux-docs	✅ Ready (Inspect)	Visit Preview	May 20, 2022 at 1:24PM (UTC)

[sspencerwire]

@ressonix I've checked with @wsoyinka and he is OK with adding this language to facilitate a new translator.

[FoggyMtnDrifter]

LGTM :+1: