Feature Request: Add ability to set the domain that is as default

[cmarabate]

I notice that every time I click home and choose a different type of device, it reverts back to opening https://virejdasani.github.io/Responsivize/ in each device instead of the URL I changed it to.

I think it should either save the URL you change it to to be used everywhere or add somewhere that we can change what the default URL is set to.

[virejdasani]

@cmarabate, thanks for letting me know, I've added this to my todo list. However, I have my exams soon so I won't be able to do this right now. if you'd like, you can implement this and open a pull request which I'll merge :)
If that's not possible, I'll get this done once my exams are over!