Update dependencies to latest versions

[rukai]

All the npm dependencies in use by this project should be updated to their latest version.
e.g. vitepress is currently on ^1.0.0-alpha.29 but 1.0.0-beta.1 has since been released.
and also:

A tangible benefit would be being able to checkin #8
But it is also just generally favorable to be up to date on our deps, in case we need a bug fix from upstream.

I did notice some strange changes to the formatting while testing #8, maybe our custom theming css needs to be adjusted with the new version of vitepress?