Make users aware of submission guidelines when they add a talk

[schultyy]

Currently people submit very short proposals, put links to slides in there, things addressed in the guidelines https://cfp.eurucamp.org/guide.

To address this, we could enhance the cfp in a way where users get notified immediately when something is wrong/not optimal like:

• (too) short description
• links in the description
• their own name in the description
• ...

This should appear as a warning when they're on the submission screen.

[bitboxer]

Whe should also do a validation of the text and make them acutally confirm that this is what they want.

Things to check:

• Twitter Handles
• Youtube Links
• Gender pronouns
• Website links in general
• email

[bitboxer]

Can we also try to find names and warn the user about that, too?