Need Grab-and-Go publication pages

[rickmcgeer]

This is a request from a number of users. Key steps:

1. Generate version of published that doesn't take dashboard from inputs but instead looks in its own directory for dashboard file
2. Add command to dashboard/extension which drops tarball in user's JupyterLab directory

(2) is the challenge, because it requires either adding code to the extension (menu item) or widget on studio page and plumbing back to JuptyerLab (or download tarball to user's disk)

Assigned to group for discussion on UI issues, hostsing.