Fix broken link in README.md

[wren]

This was originally reported in #74, but it appears to have been overlooked in favor of the other problem in that same issue.

Changes

• Fix broken link

Checklist

• [ ] Added tests (if necessary)
• [x] Updated docs or README...

[wren]

Closing because I didn't see that there was already another PR (#113) open for the same fix.