[chore] Add proper api spec schema for Available_AssigneesModel

docs/api/apiv3/components/schemas/available_assignees_model.yml

@@ -1,56 +1,32 @@
 # Schema: Available_AssigneesModel
 ---
-type: object
-example:
-  _links:
-    self:
-      href: "/api/v3/projects/42/available_assignees"
-  total: 2
-  count: 2
-  _type: Collection
-  _embedded:
-    elements:
-    - _type: User
+allOf:
+  - "$ref": "./collection_model.yml"
+  - type: object
+    required:
+      - _links
+      - _embedded
+    properties:
       _links:
-        self:
-          href: "/api/v3/users/1"
-          title: John Sheppard - j.sheppard
-        lock:
-          href: "/api/v3/users/1/lock"
-          title: Set lock on j.sheppard
-          method: POST
-        delete:
-          href: "/api/v3/users/1"
-          title: Delete j.sheppard
-          method: DELETE
-      id: 1
-      login: j.sheppard
-      firstName: John
-      lastName: Sheppard
-      email: [email protected]
-      avatar: https://example.org/users/1/avatar
-      status: active
-      createdAt: '2014-05-21T08:51:20.977Z'
-      updatedAt: '2014-05-21T08:51:20.977Z'
-    - _type: User
-      _links:
-        self:
-          href: "/api/v3/users/2"
-          title: Jim Sheppard - j.sheppard2
-        lock:
-          href: "/api/v3/users/2/lock"
-          title: Set lock on j.sheppard2
-          method: POST
-        delete:
-          href: "/api/v3/users/2"
-          title: Delete j.sheppard2
-          method: DELETE
-      id: 2
-      login: j.sheppard2
-      firstName: Jim
-      lastName: Sheppard
-      email: [email protected]
-      avatar: https://example.org/users/1/avatar
-      status: active
-      createdAt: '2014-05-21T08:51:20.977Z'
-      updatedAt: '2014-05-21T08:51:20.977Z'
+        type: object
+        required:
+          - self
+        properties:
+          self:
+            allOf:
+              - "$ref": "./link.yml"
+              - description: |-
+                  The available assignees collection
+
+                  **Resource**: AvailableAssigneesCollection
+                readOnly: true
+      _embedded:
+        type: object
+        properties:
+          elements:
+            type: array
+            readOnly: true
+            items:
+                allOf:
+                - "$ref": "./user_model.yml"
+                - description: Collection of Users