Merge branch 'tools-ynl-rst-display-attribute-set-doc'

Matthieu Baerts says:

====================
tools: ynl: rst: display attribute-set doc

Some attribute-set have a documentation (doc:), but they are not
displayed in the RST / HTML version. This series adds the missing
parsing of these 'doc' fields.

While at it, it also fixes how the 'doc' fields are declared on multiple
lines.
====================

Link: https://patch.msgid.link/20250913-net-next-ynl-attr-doc-rst-v3-0-4f06420d87db@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>