Cleanup of the kpt cli

[liamfallon]

Below is a survey of the current kpt CLI commands.

We should review this list and decide what we support and what level of support we give to what.

✓ kpt alpha      license
?                live     apply
?                         plan
?                rollouts advance
?                         get
?                         stats
✓                wasm     pull           # From OCI
✓                         push           # To OCI
✓     completion          bash
✓                         fish
✓                         powershell
✓                         zsh
✓     fn                  doc
✓                         eval
✓                         render
✓                         sink           # To local disk
✓                         source         # From local disk
✓     help
✓     live                apply
✓                         destroy
✓                         init
?                         install-resource-group
?                         migrate
✓                         status
✓     pkg                 diff           # Compared to upstream
✓                         get
✓                         init
✓                         tree
✓                         update
✓     vesion

✓: Looks good
x: Should be removed
?: unclear

[CsatariGergely]

I would apply the following logic for the ? ones:
If we can not post a reason here until wk47 (week after KubeCon), then let's remove them.