feat: Add Vue3 exercises and interview plan

- Introduced Vue3 exercises covering composable API, reactivity, lifecycle hooks, and built-in components.
- Added structured interview plan for frontend candidates focusing on HTML, CSS, JavaScript, TypeScript, and Vue.
- Included starter files for each exercise and detailed README documentation for guidance.

08-vue3/02-reactive-and-computed/starter.js

@@ -0,0 +1,26 @@
+const { createApp, reactive, computed } = Vue;
+
+createApp({
+  setup() {
+    const course = reactive({
+      title: "Vue3 响应式基础",
+      totalLessons: 10,
+      finishedLessons: 3,
+    });
+
+    const progressText = computed(() => {
+      // 任务：返回类似 “当前已完成 3 / 10 节”
+      return "";
+    });
+
+    function finishOneLesson() {
+      // 任务：在不超过总课时的前提下，finishedLessons 加 1
+    }
+
+    return {
+      course,
+      progressText,
+      finishOneLesson,
+    };
+  },
+}).mount("#app");