Entering the app through a subdirectory/path leads to a GH Page 404

[wrynearson]

In #15 and #17, URL routing was added. While the URL updates when a run, page, or URL search parameters are used, the page is not accessible when entering the app directly from a URL other than the root URL.

E.g., https://willwill.run/12734275064 leads to a GH page 404 error.