[Improvement] Reorganize demos (#1052)

packages/stepper/demo/index.vue

@@ -0,0 +1,41 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-stepper v-model="stepper1" />
+    </demo-block>
+
+    <demo-block :title="$t('disabled')">
+      <van-stepper v-model="stepper1" disabled />
+    </demo-block>
+
+    <demo-block :title="$t('advancedUsage')">
+      <van-stepper
+        v-model="stepper2"
+        integer
+        :min="5"
+        :max="40"
+        :step="2"
+        :default-value="9"
+      />
+    </demo-block>
+  </demo-section>
+</template>
+
+<script>
+export default {
+  data() {
+    return {
+      stepper1: 1,
+      stepper2: null
+    };
+  }
+};
+</script>
+
+<style lang="postcss">
+.demo-stepper {
+  .van-stepper {
+    margin-left: 15px;
+  }
+}
+</style>