Prepare for adding theseus

apps/theseus-gui-tpl/src/main.ts

@@ -0,0 +1,12 @@
+import './styles.scss';
+
+import router from './router';
+
+import { createApp } from 'vue';
+import App from './app/App.vue';
+
+const app = createApp(App);
+
+app.use(router);
+
+app.mount('#root');