Problem

When an admin starts a new deployment of Coder, they must create the first user through CLI, but this is not obvious.

Initial Solution

Have the frontend detect whether the first user has been created. If not, have it display CLI instructions.

Eventual Solution

Replace the CLI instructions with a sign-up page so that the admin can do create their user through the UI.

Definition of Done

• In a deployment with no users, the login page redirects to a page that displays instructions on how to create the first user through the CLI
• A deployment with at least one user has no change

Notes

Here's what the signup flow looks like from the CLI: https://asciinema.org/a/cy8QVTPwazDAV6cxcV6DF1Qnj

Here's where initial user creation is implemented in the CLI: https://github.com/coder/coder/blob/v0.8.1/cli/login.go#L81-L196