[REQUEST] Add adventures to multiple collections

[Ave-Rechts]

Is your feature request related to a problem? Please describe.
I like to use collections as my vacation plans. And sometimes in my lifetime, I visit the same activity, region or country more than once. It would be nice to be able to add the same adventure to multiple collections, since u can already do multiple visits on one adventure.

Describe the solution you'd like
Possibility to add a specific adventure to more than one collection.