docs(SSL): restore socket-derived attributes on Connection page (#1465)

[LeSingh1]

Fixes #1465.

The Connection API page lost every socket.socket-derived method (bind, listen, fileno, getsockname, getpeername, setsockopt, etc.) when the docs migrated to autoclass. Those methods are not defined on OpenSSL.SSL.Connection; they are delegated at runtime via __getattr__ to the wrapped socket, so Sphinx's autoclass introspection cannot see them.

bind() on a Connection has been in use since Cheroot 2006 and was documented through v17.5.0, but the current API page lists none of them — exactly the regression @webknjaz tracked to #737 in the issue.

Fix

Add an explicit listing of the most-frequently-used forwarded methods under the autoclass block with one-line descriptions and :py:meth: links back to the socket.socket reference. Closes the doc gap without touching runtime behavior. The trailing paragraph also notes the issue's second action item — new server-side code should generally bind the underlying socket directly rather than go through the Connection proxy.

Verification

$ sphinx-build -W -b html doc doc/_build/html
... build succeeded.

$ grep -c 'Connection.bind\|Connection.listen\|Connection.fileno' doc/_build/html/api/ssl.html
12

The rendered api/ssl.html now contains Connection.bind, Connection.listen, Connection.fileno, Connection.getsockname, Connection.getpeername, Connection.setsockopt, Connection.getsockopt, and the timeout/blocking accessors.

No code change; behavior is unaffected. Docs-only.