Add documentation to codespell CI

Author: jeff5

.github/workflows/codespell.yml

@@ -18,4 +18,5 @@ jobs:
     - run: pip install codespell
     - run: codespell --count --ignore-words=Misc/codespell/words.ignore
                   NEWS README.md README.txt LICENSE.txt Misc/INDEX Misc/codespell/README
+                  Doc InternalDocs ProcessDocs