This is because mini-css-extract-plugin had a internal change at https://github.com/webpack-contrib/mini-css-extract-plugin/pull/265 which will cause issue to VuePress.

Updated URL of docs (v0.vuepress.vuejs.org) to fix broken link

When running vuepress dev, chorkidar is set to observe all
addition/removal of md files inside the entity folder.

`node_modules` is one of these folders and can contain tons of
subfolders. It mostly never contains any md files anyway, and
even rarely has any hot additions of md files.

Another perk of this perf fix is this: If for some reason a developer
decided to publish a folder with a weird name in its module. It will not
prevent `vuepress dev` from loading.

to avoid ! error: `-bash: !": event not found`

header will not be detected when some content are placed before h1

Minor improvements to the service workers section of the theme docs

This reverts commit 0bc2b51e.

 Bump downstream dep "register-service-worker" since https://github.com/yyx990803/register-service-worker/pull/9 has been merged.