v0.7.0

Added

• Require Volt 0.21. The dev server gives Volt a way to render pages, so that with Volt's morph setting each open page is told what changed instead of requesting itself again: its text, the attributes of <html> and <body>, and metadata in <head> update in place.
• An island whose props changed on the server re-renders in place with the new props, instead of the page reloading. Vue, React and Solid islands keep their state. A Svelte island is mounted again, because props passed to mount are not reactive, so its state resets.