bpo-40066: Enum: modify `repr()` and `str()` (GH-22392)

* Enum: streamline repr() and str(); improve docs

- repr() is now ``enum_class.member_name``
- stdlib global enums are ``module_name.member_name``
- str() is now ``member_name``
- add HOW-TO section for ``Enum``
- change main documentation to be an API reference
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index 31d804c..30b3c5e 100755
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -785,9 +785,9 @@
    system if IPv6 isn't enabled)::
 
       >>> socket.getaddrinfo("example.org", 80, proto=socket.IPPROTO_TCP)
-      [(<AddressFamily.AF_INET6: 10>, <SocketType.SOCK_STREAM: 1>,
+      [(socket.AF_INET6, socket.SOCK_STREAM,
        6, '', ('2606:2800:220:1:248:1893:25c8:1946', 80, 0, 0)),
-       (<AddressFamily.AF_INET: 2>, <SocketType.SOCK_STREAM: 1>,
+       (socket.AF_INET, socket.SOCK_STREAM,
        6, '', ('93.184.216.34', 80))]
 
    .. versionchanged:: 3.2