Vue compat build: `template: <App/>` doesn't render app

[jeremiahvpratt]

In Vue 2, this is valid syntax to render the component "App":

new Vue({
  components: { App },
  template: '<App/>',
});

In the Vue 3 compat build, this appears to silently fail, while only the below syntax is supported:

new Vue({
  components: { App },
  render: (h) => h(App),
});

This silent failure sent me down a bit of a rabbit hole trying to get my app to render in the compat build. This definitely needs to be added to the migration guide as something to check for if it can be replicated.