Add feedback channel

[NMertsch]

Seen at PyCon DE/PyData 2025:

Add a dedicated channel for attendees to provide feedback on the conference.

To consider:

• Moderation: Does such a channel encourage negative behavior?
  • Let's see. We can always close/restrict/delete the channel if there are issues.
• Text or Forum channel? PyCon DE had a text channel, and participants discussed multiple topics in parallel. It sometimes got hard to follow. A forum could facilitate on-topic discussions, and we could block attendees from commenting (either from the start, or if things get heated).
  • Let's do a Forum channel.