[smalldet] add readme infer result (#6573)

readme add infer result

configs/smalldet/README.md

-简体中文 | [English](README.md)
-
 # PP-YOLOE Smalldet 检测模型
 
+<img src="https://user-images.githubusercontent.com/82303451/182520025-f6bd1c76-a9f9-4f8c-af9b-b37a403258d8.png" title="VisDrone" alt="VisDrone" width="300"><img src="https://user-images.githubusercontent.com/82303451/182521833-4aa0314c-b3f2-4711-9a65-cabece612737.png" title="VisDrone" alt="VisDrone" width="300"><img src="https://user-images.githubusercontent.com/82303451/182520038-cacd5d09-0b85-475c-8e59-72f1fc48eef8.png" title="DOTA" alt="DOTA" height="168"><img src="https://user-images.githubusercontent.com/82303451/182524123-dcba55a2-ce2d-4ba1-9d5b-eb99cb440715.jpeg" title="Xview" alt="Xview" height="168">
+
 
 |    模型   |       数据集     |  SLICE_SIZE  |  OVERLAP_RATIO  | 类别数  | mAP<sup>val<br>0.5:0.95 | AP<sup>val<br>0.5 | 下载链接  | 配置文件 |
 |:---------|:---------------:|:---------------:|:---------------:|:------:|:-----------------------:|:-------------------:|:---------:| :-----: |