[Doc] beautify demo

packages/number-keyboard/demo/index.vue

@@ -1,7 +1,10 @@
 <template>
   <demo-section>
     <demo-block :title="$t('default')">
-      <van-button @touchstart.stop="keyboard = 'default'">
+      <van-button
+        type="primary"
+        @touchstart.stop="keyboard = 'default'"
+      >
         {{ $t('button1') }}
       </van-button>
 
@@ -16,7 +19,10 @@
     </demo-block>
 
     <demo-block :title="$t('custom')">
-      <van-button @touchstart.stop="keyboard = 'custom'">
+      <van-button
+        type="primary"
+        @touchstart.stop="keyboard = 'custom'"
+      >
         {{ $t('button2') }}
       </van-button>
 

packages/number-keyboard/test/__snapshots__/demo.spec.js.snap

@@ -2,7 +2,7 @@
 
 exports[`renders demo correctly 1`] = `
 <div>
-  <div><button class="van-button van-button--default van-button--normal"><span class="van-button__text">
+  <div><button class="van-button van-button--primary van-button--normal"><span class="van-button__text">
       弹出默认键盘
     </span></button>
     <div class="van-number-keyboard van-number-keyboard--default" style="z-index: 100;" name="van-slide-up">
@@ -10,7 +10,7 @@ exports[`renders demo correctly 1`] = `
       <div class="van-number-keyboard__body"><i class="van-hairline van-key">1</i><i class="van-hairline van-key">2</i><i class="van-hairline van-key">3</i><i class="van-hairline van-key">4</i><i class="van-hairline van-key">5</i><i class="van-hairline van-key">6</i><i class="van-hairline van-key">7</i><i class="van-hairline van-key">8</i><i class="van-hairline van-key">9</i><i class="van-hairline van-key van-key--gray">.</i><i class="van-hairline van-key">0</i><i class="van-hairline van-key van-key--gray van-key--delete">删除</i></div>
     </div>
   </div>
-  <div><button class="van-button van-button--default van-button--normal"><span class="van-button__text">
+  <div><button class="van-button van-button--primary van-button--normal"><span class="van-button__text">
       弹出自定义键盘
     </span></button>
     <div class="van-number-keyboard van-number-keyboard--custom" style="z-index: 100; display: none;" name="van-slide-up">