Documentation Request: working RoleTemplate, AccessBinding, role and RBAC permission examples

[matt-land]

This was an area my team struggled to get this working out of box.
I think having an out of box example here will help with adoption of this plug.
What would have helped us is more "canned" assets that get to a working demo state on our Argo Sandbox with less effort.
The actual permissions of the roles don't matter, as long as they can invoke the permissions button.

Define three roles

• a read only role
• a role that has some additional permissions (limited operator), the access binding, and the role template to request it with GUID 1
• a role that has more more permissions (limited admin), the access binding, and the role template to request it with GUID 0

Define a simple RBAC example I can drop with minor edits.

[leoluz]

@matt-land I added the information that I initially thought would be enough in the README. However, as someone who designed and implemented this extension, I understand that it might be lacking some basic guidance.
I also think that it would be great to have a new folder under the examples with a working configuration for a demo. Is this something that your team could contribute to the project?

[FrederiqueRetsema]

I was already working on something like this, see #116

[leoluz]

@FrederiqueRetsema Awesome! I'll review the PR and give it a try locally. Thank you.

Also, anybody using this extension in a corporate environment, please sign the USERS.md.