chore: add type attr to button (#42)

Author: ubugeeei

content/1.vue/.template/files/app.vue

@@ -4,7 +4,7 @@ const count = ref(0)
 </script>
 
 <template>
-  <button @click="count++">
+  <button type="button" @click="count++">
     Count is: {{ count }}
   </button>
 </template>

content/1.vue/2.reactivity/.template/files/app.vue

@@ -11,7 +11,7 @@ function increment() {
   <div>
     <p>count is {{ count }}</p>
     <p>doubled is {{ doubled }}</p>
-    <button @click="increment">
+    <button type="button" @click="increment">
       +1
     </button>
   </div>

content/1.vue/2.reactivity/.template/solutions/app.vue

@@ -15,10 +15,10 @@ function multiply() {
   <div>
     <p>count is {{ count }}</p>
     <p>result is {{ result }}</p>
-    <button @click="increment">
+    <button type="button" @click="increment">
       +1
     </button>
-    <button @click="multiply">
+    <button type="button" @click="multiply">
       x{{ multiplier }}
     </button>
   </div>