Fix typos with codespell

Using codespell 2.2-dev from current git.

Added `misc/scripts/codespell.sh` to make it easier to run it once in a
while and update the skip and ignore lists.

(cherry picked from commit 1bdb82c64e)

editor/rename_dialog.cpp

@@ -535,7 +535,7 @@ String RenameDialog::_postprocess(const String &subject) {
 		// To Lowercase
 		result = result.to_lower();
 	} else if (case_id == 2) {
-		// To Upercase
+		// To Uppercase
 		result = result.to_upper();
 	}