when running `keybase track` logged out, more helpful error message needed

it should suggest one of these, with pretty explanation of each:

`keybase login` - if you already have an account
`keybase signup` - if you don't
`keybase id` - if you just want to look someone up

Start by reproducing `keybase track` while logged out and locate the CLI entry point that produces its current error. Update the message to explain and suggest `keybase login`, `keybase signup`, or `keybase id`, then verify the logged-out command shows all three options.

Written by the indexing model from the issue text.