juju permission levels should be documented in 'juju help grant'

[David Britton]

What I exepect at a minimum:

short description (one line) of what 'read, write, admin, login, add-model, superuser' grant me.

What would be nice:

longer description maybe under `juju help permissions` or something like that. Or even a pointer to online docs?

Current Display: (juju 2.1b5)

dpb@helo:charms[0]$ juju help grant
Usage: juju grant [options] <user name> <permission> [<model name> ...]

Summary:
Grants access level to a Juju user for a model or controller.

Options:
-B, --no-browser-login (= false)
    Do not use web browser for authentication
-c, --controller (= "")
    Controller to operate in

Details:
By default, the controller is the current controller.

Users with read access are limited in what they can do with models:
`juju models`, `juju machines`, and `juju status`.

Valid access levels for models are:
    read
    write
    admin

Valid access levels for controllers are:
    login
    add-model
    superuser

Examples:
Grant user 'joe' 'read' access to model 'mymodel':

    juju grant joe read mymodel

Grant user 'jim' 'write' access to model 'mymodel':

    juju grant jim write mymodel

Grant user 'sam' 'read' access to models 'model1' and 'model2':

    juju grant sam read model1 model2

Grant user 'maria' 'add-model' access to the controller:

    juju grant maria add-model

See also:
    revoke
    add-user

[Paul Collins (pjdc)]

The help text now (as of 2.9.4) includes examples, but the `add-model` controller permission is still not mentioned:

```
Valid access levels for controllers are:
    login
    superuser
```

[Canonical Juju QA Bot (juju-qa-bot)]

This Medium-priority bug has not been updated in 60 days, so we're marking it Low importance. If you believe this is incorrect, please update the importance.