doc: add tls.parseCertString()
Refs: https://github.com/nodejs/node/issues/14193
Checklist
-
documentation is changed or added -
commit message follows commit guidelines
Affected core subsystem(s)
doc, tls
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Refs: https://github.com/nodejs/node/issues/14193
doc, tls