Add additional warning/information for Hide your Referrer from third-parties

[AdamWr]

Hide your Referrer from third-parties is one of the most problematic Stealth mode option, so I think that it would be a good idea to add additional information/warning below this option (like for instance in Block the third-party Authorization header).

https://github.com/AdguardTeam/AdguardFilters/issues/70297#issuecomment-752844191