Disable QR code for stackblitz

[pi0]

(shared by @manniL in a private discussion)

We added a QR code to the listhen banner a while ago as a DX enhancement also enabled it for stackblitz. And I used it for several times in order to test my sandbox on phone.

Do you belive it is an extra feature? We might think to remove it since was experimental anyway.

(waiting for feedbacks for a while on this issue)

[manniL]

Happy to share my 2 cents here:

I used it 1 or 2 times so far and probably started the dev server several 100, if not 1000 times in the meantime.
Maybe a generation on demand (e.g. shortcut via terminal as DX improvements) could be nice in addition to a command flag? 😋

[pi0]

I like the shortcut to show idea. (i hope it works in stackblitz too btw!) specially that we already plan for shortcuts support here in listhen.