Unclear Documentation - Room Encryption

### Steps to reproduce

Hello!

I was trying to understand privacy on Element and what is "public" when a room is E2E encrypted. Namely:
- Is the topic of the room also Encrypted?
- How do widgets work? Does still the Homeserver have access to the contents of them?

Thank you!

### Outcome

#### What did you expect?

To find a response on Topic encryption when E2EE is enabled.

#### What happened instead?

Searched for 2 hours and I was unable to find the response

### Your phone model

_No response_

### Operating system version

_No response_

### Application version and app store

_No response_

### Homeserver

_No response_

### Will you send logs?

No

### Are you willing to provide a PR?

No