Enhance examples and documentation for role assignments, adding scenarios for multiple principals and role constraints

examples/scenario-1.tfvars.json

@@ -0,0 +1,30 @@
+{
+  "principals": {
+    "principal1": {
+      "principal_name": "sp-principal1",
+      "principal_type": "User",
+      "roles": [
+        "Reader"
+      ]
+    },
+    "principal2": {
+      "principal_name": "sg-admins",
+      "principal_type": "Group",
+      "roles": [
+        "Contributor"
+      ]
+    },
+    "principal3": {
+      "principal_name": "john.doe@example.com",
+      "principal_type": "User",
+      "roles": [
+        "Owner"
+      ],
+      "restricted_roles": [
+        "Owner",
+        "User Access Administrator",
+        "Role Based Access Control Administrator"
+      ]
+    }
+  }
+}