Customize QR Link when using selfhosted version (or for github pages using cli)

[eljojo]

As a follow up to #9, we missed the feature of customizing the QR link on #88

[iyiola-dev]

hi @eljojo can i get on this?

[eljojo]

@iyiola-dev yes!

I'm thinking, when using the cli, a parameter can be used to set the URL.

For the web UI, I'm not so sure, I want it to be very minimal. Maybe when starting the self hosted server, you can specify a "public URL", and if you specify it, the QRs are generated pointing to it instead of the github.io website?