Make API key more easily available after creating a new account

[Gankra]

Not very discoverable, especially since this is probably the first thing you're interested in getting after registering. Resetting it should definitely be in there, but that's certainly not where I would expect to go for "what is my API key".

Possible solution: redirect new logins and/or registrations to there.

[wycats]

@gankro agreed.

[wycats]

The CLI should also make it discoverable.

[alexcrichton]

Right now you can type cargo login <token> at the CLI, but you can't discover your own token through the CLI b/c we require a github login (which cargo itself doesn't want to mess with)

[locks]

What needs to happen to resolve this issue?

[carols10cents]

What happens today when you're a new user of crates.io:

You visit crates.io and see this:

So you click "Log in with GitHub", do the oAuth dance, and you're taken... back to the homepage, only now your icon is in the upper right:

There's not really a call to action, you have to notice there's a little triangle next to your icon that opens this menu:

and the menu item you want is "account settings", which is the crates.io/me page where you can verify your email and create API tokens:

The smallest change is probably adding a notice at the top of the page that says something like "Welcome to crates.io! Visit account settings to verify your email address and create an API token!".

Ideally, we'd only show that if we just created an account rather than updating one in the NewUser create_or_update method. I think we can send that info to the frontend here from the backend controller action associated with /authorize.

Other changes I could see that seem more complex:

• Always redirecting to /me after logging in (not sure if that's the best experience either)
• Customizing the message shown based on whether the user needs to verify their email, create an API token, or both (account completion percentage sort of?)
• Always showing a notice on every page until the user verifies their email and creates an API token, could be annoying

I'm open to thoughts based on what people think the best experience would be and what seems possible/easy to implement!