Adding a few files which are currently not used before a huge refactoring...

src/lib/pubsub.ts

@@ -0,0 +1,25 @@
+/**
+ *
+ * See https://www.pluralsight.com/guides/how-to-communicate-between-independent-components-in-reactjs (and many similar pages)
+ *
+ *
+ */
+
+const eventBus = {
+  on(event: string, callback: any) {
+    // ...
+    document.addEventListener(event, (e) => callback(e));
+  },
+
+  dispatch(event: string, data: any) {
+    // ...
+    document.dispatchEvent(new CustomEvent(event, { detail: data }));
+  },
+
+  remove(event: string, callback: (e: Event) => void) {
+    // ...
+    document.removeEventListener(event, callback);
+  },
+};
+
+export default eventBus;