Add device support github template

[pimlie]

What you want:

Add a github issue template with which users can share supported devices.

Long run we should probably add an export method to the app so they can copy stuff like discovered device features/services/characteristics into the template so we have a full reference.

Why you want it:

If #432 gets merged then it adds documentation about bluetooth support. Including a list of known working devices could be very valuable, so preferably we should make it easy for users to report devices but also force them to specify the information we need to add them to that bluetooth page.

[dp35654]

How do I get this off my phone? Never installed it