ui: Begin GUI

The GUI shows a screenshot of each monitor, as well as the title and URL
of the page being displayed.  There's also a button to trigger a page
reload on the remote machine.

ui/src/plugins/vuetify.ts

@@ -0,0 +1,10 @@
+import Vue from "vue";
+import Vuetify from "vuetify/lib";
+
+Vue.use(Vuetify);
+
+export default new Vuetify({
+  theme: {
+    dark: true,
+  },
+});