doc: add a reference to the list of OpenSSL flags.

Some of the SSL_OP_* constants are missing description in the
documentation. Instead of rewriting the description from OpenSSL's
wiki, I have decided to put a link to a detailed list in the
'OpenSSL Options' section.

I see no point of doing both - adding a reference to the wiki and
adding constant descriptions - but I might do if presented with
convincing arguments.

This is a follow-up to #33929.

PR-URL: https://github.com/nodejs/node/pull/34050


Reviewed-By: James M Snell <jasnell@gmail.com>