Add a "back" link to the navigation

[nickcharlton]

This solves half of #271 by implementing a link to take the user back to
the main application. It's assumed that root_url without a namespace
returns the main application's root.

[nickcharlton]

@tysongach, as someone who's worked on the design here quite a bit, I'd love some input on how to improve this link.

Currently, it looks like:

But it feels to me that the location of the text here is wrong. What do you think?

[LkeMitchll]

@tysongach, as someone who's worked on the design here quite a bit, I'd love some input on how to improve this link.

Currently, it looks like:

But it feels to me that the location of the text here is wrong. What do you think?

@nickcharlton If it were me I would more clearly separate this function away from the other items, as it is a contextually destructive (it tears you away from Administrate completely) action. Perhaps try a style closer to a button, vertically align it to the main heading, and then add whitespace below to clearly separate the items:

In this image I've mocked an alternative button style that may not exist in the styling, but It's fairly important that this isn't too bold or distracting, in my opinion. I'd also like to see a 'back arrow' button inside it, but that's a nice-to-have, for sure.

[nickcharlton]

I've made those changes (trying to make it fit as well as I can into Administrate). What do you think? https://administrate-demo-prer-pr-1376.herokuapp.com/admin

[LkeMitchll]

LGTM

[sedubois]

NB: the README's screenshot does not include this change.

[nickcharlton]

Oh thanks for pointing that out! I did that here: #1523