Feature: Improve documentation for SSH login

### Is there an existing request for this feature?

- [X] I have searched the existing issues and found none that matched mine

### Describe the feature

I have attempted to follow the documentation for SSH login and am finding it very unclear.

I follow it to the screenshot of a terminal emulator with two options:

1 - local password authentication
2 - Device authentication

and see "2" was selected.

It doesn't show what to do after this step. When I do this step, it makes me sign in with entra id, but then it asks for a local password to be set. I can then login using only that password, from any machine on the network

I am trying to authenticate users on an Ubuntu machine using the same credentials as their Microsoft email accounts. We want MFA each time they login. Is this possible with `authd`?

### Describe the ideal solution

Documentation explaining what "Local Password Authentication" and "Device Authentication".

Expanded tutorial showing what an ssh login should look like.

### Alternatives and current workarounds

I have not found a workaround using authd. It seems like it just allows password-based login from any machine after the account has been set up?

An alternative may be himmelblau. It is a similar project which allows for MFA entra id ssh login. There is a video showing MFA ssh login on the github page: https://github.com/himmelblau-idm/himmelblau

### System information and logs

### Environment

* broker version: 0.1+267a15c.f272cc1
* authd version: 0.3.6
* gnome shell version: N/A
* Distribution: Ubuntu
* Distribution version: 24.04

### Log files

Nothing Relevant

### Relevant information

Nothing Relevant

### Double check your logs

- [X] I have redacted any sensitive information from the logs