chooseGroup is lacking documentation

[rizen]

https://docs.boardzilla.io/api/classes/Action#choosegroup

chooseGroup only shows 1 example, but it has 4 choice types. Each of the choice types should have an example.

Also, it appears that the type called board may be unnecessary since chooseFromBoard has a number attribute. But then again, once this choice has documentation, it might be clear why it should exist in chooseGroup.