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

[Eli Zaretskii]

> From: Theodor Thornhill <theo@thornhill.no>
> Cc: 60983@debbugs.gnu.org
> Date: Sat, 28 Jan 2023 14:12:52 +0100
> 
> > Yuan or Theo, would one of you please make the change of making
> > treesit-font-lock-level a defcustom, with a proper :set functions to
> > avoid the need to revisit the file?  My hands are too full ATM, and
> > this issue is basically the only one which prevents me from updating
> > the Emacs user manual with the tree-sitter info, which in turn is the
> > only issue that blocks the move to releasing the 29.0.90 pretest
> > tarball.
> >
> > TIA
> 
> 
> Are you okay with these patches, Eli? If so, then I can clean them up a
> little and install on emacs-29.  In both cases using
> (customize-set-variable 'the-variable val) will take effect in the
> buffer without having to reload anything.

LGTM, please install, and thanks.

> Let me know if there are any other changes needed.  I'll have some time
> this evening to do some hacking if needed :)

Will do.