BUG: `Edit on Github` goes to 404 for transcluded pages

[corneliusroemer]

When clicking the Edit on Github button at the top right on the beast guide page: https://docs.nextstrain.org/en/latest/guides/bioinformatics/import-beast.html, one ends up with a 404 Github error: https://github.com/nextstrain/docs.nextstrain.org/blob/master/src/guides/bioinformatics/import-beast.md

The page actually lives here: https://github.com/nextstrain/augur/blob/f4e46fba552297577dcbbc0bd3644639452a1591/docs/faq/import-beast.md?plain=1#L1

There are probably a few other doc pages with the same bug, possibly all those here: https://github.com/nextstrain/docs.nextstrain.org/blob/e79ead41312c4583debc2131285a405b8a45c483/src/fetch-docs.py#L13-L24