Issue #27076: Doc, comment and tests spelling fixes

Most fixes to Doc/ and Lib/ directories by Ville Skyttä.
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index d262d99..1eadd22 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -461,7 +461,7 @@
         test and not for the other, there's a mismatch, and the test fails.
 
            ** Some format units have special funny semantics and it would
-              be difficult to accomodate them here.  Since these are all
+              be difficult to accommodate them here.  Since these are all
               well-established and properly skipped in skipitem() we can
               get away with not testing them--this test is really intended
               to catch *new* format units.