Add Russian documentation and propose language switch

[CryptAm]

What changed? Why?

• Added a full Russian translation of the documentation.

• Preserved terminology commonly used within the Web3 community.

• All technical terms, names, elements, and concepts are kept in English where they are not translated or are conventionally used in their original form within the Web3 community.

• No technical logic or code behavior was modified - only documentation text, comments, and explanatory content were translated.

• The original meaning and technical accuracy were preserved while making the explanations clearer and easier to understand for Russian-speaking readers.

Notes to reviewers
This translation improves accessibility for Russian-speaking developers while preserving the original meaning and technical accuracy.

This could be beneficial for the project as it may:

• Encourage contributors from other regions to add documentation translations in their native languages
• Help scale the documentation alongside the growth of the community
• Make the docs accessible to a wider audience

How has it been tested?
The translation was verified using Mintlify. I opened the documentation locally (via localhost) and visually checked that the content displays correctly, preserving the original meaning and technical accuracy.

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1