auto-update index for myst website

[dellaert]

When I preview a myst-generated website using myst start and I add index terms, the index does not auto-update the index page on the preview website. I have to kill and restart the preview. That could be by design, but it would be very cool if the index auto-updated :-)

Proposal

auto-update the index page whenever an index item was added, modified, or deleted.

Additional notes

• The new index feature is amazing, thanks @fwkoch and @rowanc1 !
• I am running myst start inside the robotics book repo.

[rowanc1]

Thanks @dellaert, this is a known limitation. Our current dependency tracking for auto reload of pages only works for includes/embedded figures, snippets etc. we aren't doing this work links/cross-refs or index because in our testing that generally leads to a full book rerender and gets pretty slow, esp on larger projects.

We have some ideas for better progressive rendering, which aim to solve this problem, as well as things like citations hanging on doi.org not stopping an intermediate preview, etc.

Going to take a bit of time to get that done though. :)