doc: update list styles for remark-parse@9 rendering

remark-parse@9.0.0 combined with our html.js tool ends a list if a
multi-line item does not include indentation. Update our docs for this
formatting.

I looked around for a lint rule to enforce this but didn't find one
readily available. (Happy to be shown that I'm wrong about that!) We may
need to write one.

PR-URL: https://github.com/nodejs/node/pull/36049


Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>