My protocol for dealing with no-PR's has been (especially in this case where you can just host the tool on github.io)

1. Just fork it and use your own version until the PR is accepted

2. Directly email the maintainer if you think your PR is worthwhile

3. If you have a bunch of PR's that are pretty useful to others, consider making it a real distributable (and not just a personal) fork if the maintainer still doesn't respond