bug#60983: 29.0.60; Tree-sitter user-level control

[Stefan Monnier]

> I asked Stefan to help precisely because I don't understand why we
> need anything beyond what we have already.  I thought mode inheritance
> should have taken care of it, or at least the documentation of
> define-derived-mode seems to imply that.

But the `define-derived-mode` uses `prog-mode` as parent, so while the
keymap does inherit from its parent mode's keymap, it's just
`prog-mode-map` rather than `c-ts-mode-map`.


        Stefan