doc: http2.connect accepts net & tls options

PR-URL: https://github.com/nodejs/node/pull/16576
Fixes: https://github.com/nodejs/node/issues/15405


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>