[v11.x backport] doc: sort bottom-of-file markdown links

Backport of https://github.com/nodejs/node/pull/24679

Preemptive, the sorting doesn't cherrypick well down to release branches, this should help prevent annoying conflicts in the docs.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines