Purge all vue-class-component with vue-facing-decorator.

Make some strike-throughs for project-task
Update package.json

src/components/HelloWorld.vue

@@ -119,15 +119,11 @@
 </template>
 
 <script lang="ts">
-import { Options, Vue } from "vue-class-component";
+import { Component, Prop, Vue } from "vue-facing-decorator";
 
-@Options({
-  props: {
-    msg: String,
-  },
-})
+@Component
 export default class HelloWorld extends Vue {
-  msg!: string;
+  @Prop msg!: string;
 }
 </script>