docs(basic): 更新 README 文档

- 调整代码示例的缩进和格式，提高可读性
- 新增 RefreshView 组件的使用示例- 更新 SafeView 组件的示例代码
- 优化 HttpHelper 相关代码示例

README.md

@@ -238,7 +238,7 @@ HttpHelper.get()
     phoneModel: 'sign',
     phoneVersion: 'sign',
     phoneBrand: 'HarmonyOS'
-    }, url.apiNo)
+}, url.apiNo)
     .then((res: HttpResult<T>) => {
     if (res.status === '0') {
         resolve(res.data as T)
@@ -246,10 +246,10 @@ HttpHelper.get()
         reject(new Error(res.message))
     }
 
-  })
+})
     .catch((error: Error) => {
     reject(error)
-  })
+})
 ```
 
 ### 3.2.postJson
@@ -268,7 +268,7 @@ HttpHelper.get()
     phoneModel: 'sign',
     phoneVersion: 'sign',
     phoneBrand: 'HarmonyOS'
-    }, url.apiNo)
+}, url.apiNo)
     .then((res: HttpResult<T>) => {
     if (res.status === '0') {
         resolve(res.data as T)
@@ -276,10 +276,10 @@ HttpHelper.get()
         reject(new Error(res.message))
     }
 
-  })
+})
     .catch((error: Error) => {
     reject(error)
-  })
+})
 ```
 
 ## 4.[自定义view](./src/main/ets/view)
@@ -333,6 +333,45 @@ build() {
 }
 ```
 
+### 4.3.[RefreshView](./src/main/ets/view/RefreshView.ets)
+
+> 下拉刷新，上拉加载更多
+
+```tsx
+import { RefreshView } from '@szyx/sdk_base'
+
+@State isLoading: boolean = false
+
+
+@Builder
+buildItem(item: Item, index: number) {
+    Column() {
+    }
+    .width('100%')
+}
+
+build() {
+    // ......
+    RefreshView({
+        isLoading: this.isLoading,
+        keyGenerator: (item: Item) => {
+            return item.id
+        },
+        pageSize: 10,
+        data: this.list ?? [],
+        customBuilderParam: this.buildItem,
+        onRefresh: () => {
+            this.refresh()
+        },
+        onLoadMore: (pageNum) => {
+            this.refresh(pageNum)
+        }
+    })
+    // ......
+
+}
+```
+
 ## 5.[Windows](./src/main/ets/utils/WindowHelper.ets)
 
 ### 5.1.弹出自定义窗口