Include RAILWAY_API_TOKEN for Account-Level Authentication for Railway CLI

[aryanprince]

Issue

The RAILWAY_API_TOKEN environment variable supports account-level authentication in the Railway CLI, but this is not documented anywhere.

Context

This information was only mentioned by @brody192 in a Railway CLI issue here, but it’s not included in the official documentation. Users like myself may not be aware of this feature, leading to confusion when trying to authenticate the CLI at an account level.

This was an issue when trying to using tools like 1Password's Shell Integration to automatically pass an API token to the CLI from your password manager's vault for example.

Suggestion

Please update the CLI documentation to include a section on using the RAILWAY_API_TOKEN variable, explaining how it can be used for account-level authentication. This should be added somewhere here where CLI authentication is explained.