Feature request: `Download Dataset` button could provide download instructions using the DANDI Client

[kabilar]

Under "Actions", it says the "Download Dataset" button is a placeholder for now.  Perhaps for this button we could provide instructions similar to what we have on DANDI Archive for using the DANDI Client to download the dataset:

For more information on the DANDI Client please see: https://docs.dandiarchive.org/api/dandi-client/

cc @satra @ayendiki @tjgrafft @francopestilli