doc: replace EOL versions in README
Node.js 14 and 15 have both reached end-of-life.
I know that 19 is not technically current, but I think it's best not to use a future LTS release line as an example of the current release line.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Node.js 14 and 15 have both reached end-of-life.
I know that 19 is not technically current, but I think it's best not to use a future LTS release line as an example of the current release line.