docs: change slot to # (#5858)

* docs(SwipeCell): change "slot" to "v-slot"

* docs(SwipeCell): change `v-slot` to`#`

* docs(cell): change `slot` to `#`

* docs(checkbox): change `slot` to `v-slot`

* docs(field): change `slot` to `v-slot`

* docs(checkbox): remove wrong comment

* docs(radio): change `slot` to `#`

* docs(search): change `slot` to `#`

* docs(slider): change `slot` to `#`

* docs(switch): change `slot` to `#`

* docs(PullRefresh): change `slot` to `#`

* docs(collapse): change `slot` to `#`

* docs(panel): change `slot` to `#`

* docs(swipe): change `slot` to `#`

* docs(navbar): change `slot` to `#`

* docs(tab): change `slot` to `#`

* docs(tabber): change `slot` to `#`

* docs(TreeSelect): change `slot` to `#`

* docs(card): change `slot` to `#`

* docs(submitBar): change `slot` to `#`

* docs(sku): change `slot` to `#` unsure

* docs(cell): delete waste blank line

* docs(panel): fix indentation

* docs(PullRefresh): change "count" to "Refresh Count"

* docs(radio): delete waste blank line

* docs(search): move props above the event

* docs(submitBar): delete waste `<span>`

* docs(swipCell): delete waste blank line

* docs(tabbar): merge `<img>` into one line

src/collapse/README.md

@@ -61,7 +61,9 @@ export default {
 ```html
 <van-collapse v-model="activeNames">
   <van-collapse-item name="1">
-    <div slot="title">Title1 <van-icon name="question-o" /></div>
+    <template #title>
+      <div>Title1 <van-icon name="question-o" /></div>
+    </template>
     Content
   </van-collapse-item>
   <van-collapse-item title="Title2" name="2" icon="shop-o">

src/collapse/README.zh-CN.md

@@ -61,7 +61,9 @@ export default {
 ```html
 <van-collapse v-model="activeNames">
   <van-collapse-item name="1">
-    <div slot="title">标题1 <van-icon name="question-o" /></div>
+    <template #title>
+      <div>标题1 <van-icon name="question-o" /></div>
+    </template>
     内容
   </van-collapse-item>
   <van-collapse-item title="标题2" name="2" icon="shop-o">