Mandatory link to discourse-thread before being able to start a challenge

Is your feature request related to a problem? Please describe.

MapRoulette is a tool and its really good and i think something good. But, maybe it makes things TO easy, as there is quite some discussion in the forum about it. I personally think one way to reduce problems is to have a mandatory link to the forum where the challenge is discussed.

It needs some discussion, of course, but problems need to be adressed.

Describe the solution you'd like

A field in the form that is mandatory with a link to the discussion forum. It should be checked and the only valid url should start with https://community.openstreetmap.org/ - no other discussion-places should be allowed because this is the place where most openstreetmap mappers are present in a kinda central place.

Describe alternatives you've considered

Additional context
https://community.openstreetmap.org/t/maproulette-critique/116922/130

Start by reviewing the challenge creation form and its existing validation flow, then read the linked OpenStreetMap community discussion for the surrounding context. Done means the form requires a discussion link and accepts only URLs beginning with https://community.openstreetmap.org/.