Merge branch 'tools-ynl-cli-improve-the-help-and-doc'

Jakub Kicinski says:

====================
tools: ynl: cli: improve the help and doc

I had some time on the plane to LPC, so here are improvements
to the --help and --list-attrs handling of YNL CLI which seem
in order given growing use of YNL as a real CLI tool.
====================

Link: https://patch.msgid.link/20260110233142.3921386-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>