tools: fix stability table generation for docs
Multi-line top-level stability indices were not working.
Refs: https://github.com/nodejs/node/pull/45335/files#r1014868777
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Multi-line top-level stability indices were not working.
Refs: https://github.com/nodejs/node/pull/45335/files#r1014868777