[new feature] Rate: add icon、void-icon prop (#2148)

packages/rate/demo/index.vue

@@ -4,9 +4,17 @@
       <van-rate v-model="value1" />
     </demo-block>
 
-    <demo-block :title="$t('customColor')">
+    <demo-block :title="$t('customIcon')">
       <van-rate
         v-model="value2"
+        icon="like"
+        void-icon="like-o"
+      />
+    </demo-block>
+
+    <demo-block :title="$t('customStyle')">
+      <van-rate
+        v-model="value3"
         :size="25"
         :count="6"
         color="#2ba"
@@ -16,7 +24,7 @@
 
     <demo-block :title="$t('disabled')">
       <van-rate
-        v-model="value3"
+        v-model="value4"
         disabled
       />
     </demo-block>
@@ -28,19 +36,22 @@ export default {
   i18n: {
     'zh-CN': {
       disabled: '禁用状态',
-      customColor: '自定义颜色'
+      customIcon: '自定义图标',
+      customStyle: '自定义样式'
     },
     'en-US': {
       disabled: 'Disabled',
-      customColor: 'Custom Color'
+      customIcon: 'Custom Icon',
+      customStyle: 'Custom Style'
     }
   },
 
   data() {
     return {
       value1: 3,
-      value2: 4,
-      value3: 2
+      value2: 3,
+      value3: 4,
+      value4: 2
     };
   }
 };