vue-demo/src/views/Home.vue

<template>
 <!-- App.vue -->
 <Main></Main>
</template>

<script>

// @ is an alias to /src
// import Main from '@/components/HelloWorld.vue'
import Main from '../components/Main.vue'

export default {
  name: 'Home',
  components: {
    Main,
  }
}
</script>