enable constraints per column+swimlane

As a GH administrator
I'd like to be able to specify issue count contraints per column and/or per swimlane

For example, I have 3 columns:

TODO, IN PROGRESS, DONE

and two swimlanes:

Expedite
Everything Else

I'd like an explicit max of 1 issue for TODO/Expedite, max of 5 for TODO/Everything Else

This could be taken further by having swimlane constraints override column constraints (so we can only have 1 expedite issue on the board at any time)