Ability to direct users back to the app after installing and onboarding

[jasperjansz]

Installing an extension to use an app (and the whole onboarding thereafter) must be pretty confusing for people unfamiliar with the process. I can imagine users who onboard through an app being pretty confused after they've installed and are looking at the empty extension home screen ("ok, now what?"). They'd have to know they need to reopen the app and refresh.

It would be great if we could know if users came from an app, and what specific URL. Then we can say: "Ok, you're all set, continue to Swapr ->" instead of showing an empty page. Metamask has a library for this purpose: https://github.com/MetaMask/metamask-onboarding.

Designs:
https://www.figma.com/file/VupGh90FJtT0dcBj2Sh7bb/%F0%9F%93%8FSpec?node-id=80%3A2592

[markmhendrickson]

@jasperjansz to review our approach here

[markmhendrickson]

@jasperjansz can you update this issue with the latest relevant design guidance and move to the bottom of the backlog?

[smcclellan]

Closing this issue due to inactivity. Feel free to reopen with any new or additional context discussed with @janniks.