Update classification_dataset_en.md

docs/en/data_preparation/classification_dataset_en.md

@@ -7,7 +7,7 @@ This document elaborates on the dataset format adopted by PaddleClas for image c
 ## Contents
 
 - [1.Dataset Format](#1)
-- [Common Datasets for Image Classification](#2)
+- [2.Common Datasets for Image Classification](#2)
   - [2.1 ImageNet1k](#2.1)
   - [2.2 Flowers102](#2.2)
   - [2.3 CIFAR10 / CIFAR100](#2.3)
@@ -16,7 +16,7 @@ This document elaborates on the dataset format adopted by PaddleClas for image c
 
 
 <a name="1"></a>
-## 1. Dataset Format
+## 1.Dataset Format
 
 PaddleClas adopts `txt` files to assign the training and test sets. Taking the `ImageNet1k` dataset as an example, where `train_list.txt` and `val_list.txt` have the following formats:
 
@@ -34,7 +34,7 @@ val/ILSVRC2012_val_00000001.JPEG 65
 
 
 <a name="2"></a>
-## 2. Common Datasets for Image Classification
+## 2.Common Datasets for Image Classification
 
 Here we present a compilation of commonly used image classification datasets, which is continuously updated and expects your supplement.