Catch local authentication attempts and give notice about guides

[benhalpern]

Is your feature request related to a problem? Please describe.

As a new user of the development app I might not have installed the oauth keys. I click to sign in with GitHub and see this...

Describe the solution you'd like

I think if we send people down this path and they don't have the right keys in the environment we redirect them to a page asking them to check the docs: https://docs.dev.to/backend/