format the application endpoint to make it obvious it's a link about spin

[itowlson]

I implemented a naive underline, and for me, it paradoxically ended up feeling less like a link because I no longer got any feedback visual feedback as I moved over it. (My terminal underlines links as I move over them, but doesn't change the cursor style; so already-underlined links appear 'dead'.) I replicated your string though and that works super nicely, I get the gentle dotted underline, and the feedback of the heavy underline when I move. Now to figure our how to implement that in our terminal crate...

(Incidentally, deploy would need to be implemented in cloud-plugin; but if we do this I'd imagine we'd also want it on spin up, so I'm leaving it here to define in a shared crate.)

NOTE TO SELF: copiable form of @ingride's string:

\e]8;;https://example.com/\e\\https://example.com\e]8;;\e\\