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

Most fixes to Doc/ and Lib/ directories by Ville Skyttä.
diff --git a/Lib/lib-tk/ttk.py b/Lib/lib-tk/ttk.py
index fe73aef..f7d0433 100644
--- a/Lib/lib-tk/ttk.py
+++ b/Lib/lib-tk/ttk.py
@@ -1014,7 +1014,7 @@
         """Begin autoincrement mode: schedules a recurring timer event
         that calls method step every interval milliseconds.
 
-        interval defaults to 50 milliseconds (20 steps/second) if ommited."""
+        interval defaults to 50 milliseconds (20 steps/second) if omitted."""
         self.tk.call(self._w, "start", interval)