feat(chat): usage improvements with hooks

1. scroll room messages to the bottom
2. submit message on `enter`

assets/js/hooks/RoomMessages.js

@@ -0,0 +1,10 @@
+const RoomMessages = {
+  mounted() {
+    this.el.scrollTop = this.el.scrollHeight;
+    this.handleEvent("scroll_messages_to_bottom", () => {
+      this.el.scrollTop = this.el.scrollHeight;
+    });
+  }
+};
+
+export default RoomMessages;