netlink: specs: team: avoid mangling multilines doc

By default, strings defined in YAML at the next line are folded:
newlines are replaced by spaces. Here, the newlines are there for a
reason, and should be kept in the output.

This can be fixed by adding the '|' symbol to use the "literal" style.
This issue was introduced by commit 387724cb ("Documentation:
netlink: add a YAML spec for team"), but visible in the doc only since
the parent commit.

To avoid warnings when generating the HTML output, and to look better,
the code layout is now in a dedicated code block, which requires '::'
and a new blank line. Just for a question of uniformity, a new blank
line is also added after the code block.

Suggested-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250913-net-next-ynl-attr-doc-rst-v3-2-4f06420d87db@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>