docs: add organizations, provisioners, and premium license docs (#14778)

- [x] Mention Orgs is beta and add a link to get feedback
- [x] Add docs on new provisioner authentication architecture and
deprecate the old one
- [x] Add/update docs for IdP sync
  - [x] Organization Sync
  - [x] Group Sync
  - [x] Role Sync
- [x] Modify `coder.com` codebase to add `Premium` and `Beta` pill, and
allow multiple pills: https://github.com/coder/coder.com/pull/638
- [x] Replace all mentions of "Enterprise" with "Premium" in docs
  - [x] edit: change it to "Licensing"
- [x] Remove the enterprise page and change all links to
coder.com/pricing
- [x] Merge #14786
- [x] Add redirects for coder.com to redirect the `using-organizations`
guide to the new orgs one and /enterprise to /premium
https://github.com/coder/coder.com/pull/645
- [x] Custom roles
- [x] https://github.com/coder/coder/pull/14786
- [x] Remove all mentions of orgs experiment
- [x] Update in-product copy & links to link to the new docs pages

Anything I am missing?

---

[Preview
this](https://coder.com/docs/@orgs-licenses/admin/organizations)

---------

Co-authored-by: Edward Angert <EdwardAngert@users.noreply.github.com>
Co-authored-by: EdwardAngert <17991901+EdwardAngert@users.noreply.github.com>
Co-authored-by: Jaayden Halko <jaayden.halko@gmail.com>

docs/admin/notifications.md

@@ -231,7 +231,7 @@ notification is indicated on the right hand side of this table.
 
 ![User Notification Preferences](../images/user-notification-preferences.png)
 
-## Delivery Preferences (enterprise)
+## Delivery Preferences (enterprise) (premium)
 
 Administrators can configure which delivery methods are used for each different
 [event type](#event-types).