Pinny should close when the browser back button is pressed

[kpeatt]

We've been getting user feedback that users expect to be able to close Pinny by pressing the browser back button on their device. This means that instead of navigating back a page, we should just close Pinny on back.

From a user's perspective, tapping back twice is easy if they want to go back a page. It is more annoying to accidentally go back a page when you don't expect to.

[scalvert]

I think we should talk about this one again. It's never come up in any feedback that I know of. If we don't need it, let's not add it!

[kpeatt]

In my UX opinion, we should add it. It's more frustrating to lose the page when you have an unknown full screen overlay than it is to have to hit back twice.

[scalvert]

I feel like this should be reserved for when someone actually logs an issue. We should take care to only 'fix' what needs fixing. If we try to fix too much, we'll end up with a bloated plugin! Thoughts?

[kpeatt]

This is more like a feature than a fix though — I don't think it would cost too many lines to add either.