message: docs(Notify): update demo
diff: <template>
  <demo-section>
  - <demo-block :title="t('basicUsage')">
  - <van-button type="danger" :text="t('basicUsage')" @click="showNotify" />
  + <demo-block card :title="t('basicUsage')">
  + <van-cell is-link :title="t('basicUsage')" @click="showNotify" />
  </demo-block>
  - <demo-block :title="t('notifyType')">
  - <div style="margin-bottom: 15px;">
  - <van-button
  - type="info"
  - :text="t('primary')"
  - @click="showType('primary')"
  - />
  - <van-button
  - type="primary"
  - :text="t('success')"
  - @click="showType('success')"
  - />
  - </div>
  -
  - <van-button
  - type="danger"
  - :text="t('danger')"
  - @click="showType('danger')"
  - />
  - <van-button
  - type="warning"
  - :text="t('warning')"
  - @click="showType('warning')"
  - />
  + <demo-block card :title="t('notifyType')">
  + <van-cell is-link :title="t('primary')" @click="showType('primary')" />
  + <van-cell is-link :title="t('success')" @click="showType('success')" />
  + <van-cell is-link :title="t('danger')" @click="showType('danger')" />
  + <van-cell is-link :title="t('warning')" @click="showType('warning')" />
  </demo-block>
  - <demo-block :title="t('customNotify')">
  - <van-button
  - type="primary"
  - :text="t('customColor')"
  - @click="showCustomColor"
  - />
  - <van-button
  - type="primary"
  - :text="t('customDuration')"
  + <demo-block card :title="t('customNotify')">
  + <van-cell is-link :title="t('customColor')" @click="showCustomColor" />
  + <van-cell
  + is-link
  + :title="t('customDuration')"
  @click="showCustomDuration"
  />
  </demo-block>
  - <demo-block :title="t('componentCall')">
  - <van-button
  - type="primary"
  - :text="t('componentCall')"
  + <demo-block card :title="t('componentCall')">
  + <van-cell
  + is-link
  + :title="t('componentCall')"
  @click="showComponentCall"
  />
  @@ -129,15 +106,3 @@ export default {
  },
  };
  </script>
  -
  -<style lang="less">
  -@import '../../style/var';
  -
  -.demo-notify {
  - background-color: @white;
  -
  - .van-button {
  - margin-left: @padding-md;
  - }
  -}
  -</style>
  