Make it easier to view a certain workspace's data

[cinnamon-bun]

Right now it says:

If you know the workspace address, you can manually craft an URL to visit it:
/workspace/+your.workspace

Add a form there so you can paste a workspace address into, which leads to the correct URL. There's no React or anything, this is all boring static HTML generated on the server.

Also consider changing the 404 page...

https://earthstar-demo-pub-v5-a.glitch.me/workspace/+your.workspace

...To include that form.

Workspace discoverability

This form would probably be hidden when the discoverable option is true and you get an easy list to pick from. But when discoverable is false, you need an easy way to paste in your workspace since you can't see it on the pub page.