fix: textarea 组件 confirm-type 属性支持 return 值 (#30)

https://developers.weixin.qq.com/miniprogram/dev/component/textarea.html

Author: skiyee

packages/uni-app-types/src/form-components/textarea.ts

@@ -17,8 +17,10 @@ type _TextareaValue = string;
  * Go 前往
  *
  * Done 完成
+ *
+ * Return 换行
  */
-type _TextareaConfirmType = "send" | "search" | "next" | "go" | "done";
+type _TextareaConfirmType = "send" | "search" | "next" | "go" | "done" | "return";
 
 interface _TextareaOnFocusDetail {
   value: _TextareaValue;