[Self-hosted] Add TURN configuration for LiveKit WebRTC if using cloudflare tunnel

What needs fixing?

The wiki that explains self hosting doesn't explain what to do to configure a TURN server. Adding it will definitely make life easier to any users that uses cloudflare tunneling.

Location

No response

Suggested change

Add a section for TURN configuration in case the user has configured cloudflare tunnel.

Checks

• I searched existing issues.
• I wrote this report in my own words, except for direct translation if needed.