feat: Document subscriptions (#3834)

Co-authored-by: Tom Moor <tom.moor@gmail.com>

app/stores/SubscriptionsStore.ts

@@ -0,0 +1,11 @@
+import Subscription from "~/models/Subscription";
+import BaseStore, { RPCAction } from "./BaseStore";
+import RootStore from "./RootStore";
+
+export default class SubscriptionsStore extends BaseStore<Subscription> {
+  actions = [RPCAction.List, RPCAction.Create, RPCAction.Delete];
+
+  constructor(rootStore: RootStore) {
+    super(rootStore, Subscription);
+  }
+}