Update PULL_REQUEST_TEMPLATE.md

Author: beckermr

.github/PULL_REQUEST_TEMPLATE.md

@@ -7,6 +7,6 @@ to `.html` files will only be effective if applied to the respective `.rst`.
 
 PR Checklist:
 
-- [ ] make all edits to the docs in the `src` directory, not in `docs`
+- [ ] make all edits to the docs in the `src` directory, not in `docs` or in the html files
 - [ ] note any issues closed by this PR with [closing keywords](https://help.github.com/articles/closing-issues-using-keywords)
 - [ ] put any other relevant information below