Fixing Bounding Box format for Text Detection isn't specified (#1734)

* Update dataset.md

* fix

---------

Co-authored-by: gaotongxiao <gaotongxiao@gmail.com>

docs/en/migration/dataset.md

@@ -123,6 +123,8 @@ The `TextDetDataset` holds the information required by the text detection task,
 }
 ```
 
+The bounding box format is as follows: `[min_x, min_y, max_x, max_y]`
+
 #### Migration Script
 
 We provide a migration script to help users migrate old annotation files to the new format.

docs/zh_cn/migration/dataset.md

@@ -123,6 +123,8 @@ img2.jpg MMOCR
 }
 ```
 
+其中，`bbox` 字段的格式为 `[min_x, min_y, max_x, max_y]`。
+
 #### 迁移脚本
 
 为帮助用户将旧版本标注文件迁移至新格式，我们提供了迁移脚本。使用方法如下：