add new FAQ entries

close #30 (closed).

asked by @stanzabird

• source#59 - accessibility
• new profile trick to diagnose problems
• China and uBo, politics and LibreWolf

asked by me:

• bookmark bar and window size
• overrides for web content language
• settings#213 (closed)
• security.cert_pinning.enforcement_level and user MiTM
• #31 (closed)
• settings#227 (comment 1193046243) --> I don't feel like we need more examples tbh
• review all existing entries