[RBAC] Make examples in rbac.md for client usage fully complete

[AlanCoding]

followup from

#45 (comment)

#45 (comment)

[AlanCoding]

also maybe #45 (comment)

[AlanCoding]

pasting from links

POST /api/v1/role_definition/ with payload

{
    "permissions": ["view_inventory"],
    "content_type": "shared.organization",
    "name": "View all org inventories",
    "description": "Custom Org Role"
}

Then do a second POST to /api/v1/role_team_assignments/ (or role_user_assignments) with a payload of:

{
    "role_definition": <id of the role created>,
    "object_id": <id of the org>,
    "team": 2
}

Maybe add a link in here reminding that you defined rd as pointing to job templates to guide users as to why this allows all JTs in an organization.

Reminder that rd is a org-type role (not job template) and lists JT permissions.