Issue #27076: Doc, comment and test function name spelling fixes

Most fixes to Doc/ and Lib/ directories by Ville Skyttä.
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 0ce80b9..4ae1e41 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -86,7 +86,7 @@
         clientTearDown ()
 
     Any new test functions within the class must then define
-    tests in pairs, where the test name is preceeded with a
+    tests in pairs, where the test name is preceded with a
     '_' to indicate the client portion of the test. Ex:
 
         def testFoo(self):