docs: fix redirect, move relation note to dropdowns

Author: tmihoc

redirects.txt

@@ -33,4 +33,4 @@ howto/setup_dashboard/ howto/manage-jimm-controllers/
 howto/bootstrap_permissions/ howto/manage-jimm-controllers/
 reference/jaas/authorisation_data/ reference/relation/
 reference/jaas/authorisation_model/ reference/relation/
-reference/jaas/authorisation/ reference/jaas/relation/
+reference/jaas/authorisation/ reference/relation/

reference/relation.md

@@ -5,6 +5,18 @@
 > See also: {ref}`manage-relations`
 
 
+```{dropdown} JAAS relations vs. Juju relations
+JAAS relations have nothing to do with {external+juju:ref}`Juju relations <relation>, which refer to the relationship, or rather integration, of two charmed applications. However, JAAS relations are related to {external+juju:ref}`Juju access levels <user-access-levels>`.
+```
+
+```{dropdown} JAAS relations vs. Juju access levels
+JAAS reshapes Juju's permission model based on access levels into the more flexible [ReBAC](https://openfga.dev/docs/authorization-concepts#what-is-relationship-based-access-control) paradigm and also expands the list of entities that can be involved in access: With Juju access levels a user is granted access to another entity. With JAAS relations, a user, service account, role or group is brought into a relation with another entity, where the relation is about access to the entity.
+
+> Note: JAAS relations are currently parallel to Juju access levels, but in the future they're expected to become a superset thereof.
+
+```
+
+
 ```{note}
 **JAAS relations vs. {external+juju:ref}`Juju relations <relation>`:** JAAS relations have nothing to do with Juju relations., which refer to the relationship, or rather integration, of two charmed applications. However, JAAS relations are related to Juju access levels.