*Build paths* can't render root page consistently

[arctic-hen7]

Describe the bug
For a template docs, using the build paths strategy, we can't render the page /docs reliably. If the page name index is used, initial loads will work, but there doesn't seem to be a way to get subsequent loads to work properly yet.

To Reproduce
As above.

Expected behavior
Using the special name index, the page should render.

Environment (please complete the following information):

• Perseus Version: v0.3.0-beta.1
• Sycamore Version: v0.6.1

Additional context
Add any other context about the problem here.

[arctic-hen7]

Okay, this works now for perseus serve by using an empty string rather than index, I'll work with exporting now.

[arctic-hen7]

Never mind, exporting seems to work perfectly! I do like when one thing fixes another, it's so rare...