Add an ID to the re-frisk debugger so it can be targeted by CSS

[Samstiles]

In my case I've got a global color: @light-green applied, which applies to the re-frisk panel, and makes it impossible to read. With an ID I can add styling to change the re-frisk CSS easily :)

[flexsurfer]

hey @Samstiles, thanks for the contribution, I'll include this in next release, but all the re-frisk features in the external window, better to use it