Feature request: device frame for simulation and demo

[knicholson32]

Describe the solution you'd like
In the online demo, and while simulating at home, the AHRS display fills the entire browser screen. Without using something like Chrome Developer Tools, it is hard to see the display as it might look on a device. It would be useful to have a way (possibly through a url variable: frame=true) to frame the display in a phone or tablet form factor. The extra space could be used to add simulation controls.

Describe alternatives you've considered
Currently can be achieved with developer tools in the browser. Not great for online demos or easy usability tests.

Additional context
General style should mimic the images on the wiki: