UI improvements: Add some more info in-app

[chirayudesai]

Let's add a start screen before we have the user note down and confirm a big passphrase.

Let's put in some info about restoring, there can be two sets of texts depending on the option enabled (SUW or in-app). This could also be kept somewhere viewable all the time, maybe below the settings entries?

[grote]

The text, design and flow should be specified here before an implementation is attempted.

[chirayudesai]

I think what we want so far is

1. A screen shown before the 12 words are shown with some details about how this works (for the user, not technical)
2. Said screen should also be accessible via the menu once setup

Longer term: 3) Users should go to a status screen, rather than directly being dropped to a screen with a combination of status and settings.