Can't find documentation on how to use vertex bones

There's very little information on how to set up/ use vertex bones. The only tutorial I've found that references them at all is one paragraph about [3d skeletons](https://docs.godotengine.org/en/3.0/tutorials/3d/working_with_3d_skeletons.html#using-3d-bones-for-mesh-control), and firstly that article doesn't exist in the latest docs, and it only says "You can directly control a group of vertices from Godot. For that please reference the MeshDataTool class and its method set_vertex_bones." The documentation for MeshDataTool::set_vertex_bones function is not helpful either.

Another possible lead (for me trying to figure it out) was in the ArrayType enum for [ArrayMesh](https://docs.godotengine.org/en/3.1/classes/class_arraymesh.html#enumerations) as in ARRAY_BONES and ARRAY_WEIGHTS, but again I don't think those are sufficiently explained either.

I also couldn't figure out how one would manipulate these bones/ vertex groups once created (like making them move), so am I misunderstanding something fundamental about what they're for and how they work?