docs(TaskProcessingApi): Cleanup endpoint descriptions

[provokateurin]

Summary

Removed unnecessary information and made the descriptions more expressive:

1. It is clear the description is about and endpoint
2. It is also clear that the endpoints act as the current user (as any endpoint does unless it is a public page or has a userId parameter)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[marcelklehr]

I don't understand the motivation for such changes to be honest, but be my guest.

[provokateurin]

It's easier to read and comprehend what is going on 🤷‍♀️ Cleaner docs are always helpful