All the armature commands are off of the `data` object in `bpy.data.armatures['Armature']` in Blender 4.0. As a result, the original commands didn't work unless `arm` was set to `bpy.data.armatures['Armature'].data`, which is different that the behavior in earlier versions. This change is to clarify how to access the collections.
- Add section on how to add/remove Bone Collection.