Update data_prepare.md (#431)

* Update data_prepare.md

* Update data_prepare.md

* Update data_prepare.md

docs/en_US/data_prepare.md

-## Data prepare
+## Data Preparation
 
-The config will suppose your data put in `$PaddleGAN/data`. You can symlink your datasets to `$PaddleGAN/data`.
+## **1. Routes Configuration of Datasets**
+
+The config will suppose your data is in `$PaddleGAN/data`. You can symlink your datasets to `$PaddleGAN/data`.
 
 ```
 PaddleGAN
@@ -28,7 +30,7 @@ PaddleGAN
 
 ```
 
-If you put your datasets on other place，for example ```your/data/path```, you can also change ```dataroot``` in config file:
+If you put the datasets on other place，for example ```your/data/path```, you can also change ```dataroot``` in config file: 
 
 ```
 dataset:
@@ -38,22 +40,30 @@ dataset:
     num_workers: 4
 ```
 
-### Datasets of CycleGAN
+## 2. Datasets Preparation
+
+### 2.1 Download of Datasets
+
+#### 2.1.1  Datasets of CycleGAN
+
+- #### Download from website
 
-#### download form website
 
-Datasets for CycleGAN can be downloaded from [here](https://people.eecs.berkeley.edu/~taesung_park/CycleGAN/datasets/)
+Datasets of CycleGAN can be downloaded from [here](https://people.eecs.berkeley.edu/~taesung_park/CycleGAN/datasets/), remember to  symlink your datasets to `$PaddleGAN/data`.
 
-#### download by script
+- #### Download by script
 
-You can use ```download_cyclegan_data.py``` in ```PaddleGAN/data``` to download datasets you wanted. Supported datasets are: apple2orange, summer2winter_yosemite,horse2zebra, monet2photo, cezanne2photo, ukiyoe2photo, vangogh2photo, maps, cityscapes, facades, iphone2dslr_flower, ae_photos, cityscapes。
+
+You can use ```download_cyclegan_data.py``` in ```PaddleGAN/data``` to download datasets you wanted. 
+
+Supported datasets are: apple2orange, summer2winter_yosemite,horse2zebra, monet2photo, cezanne2photo, ukiyoe2photo, vangogh2photo, maps, cityscapes, facades, iphone2dslr_flower, ae_photos, cityscapes。
 
 run following command. Dataset will be downloaded to ```~/.cache/ppgan``` and symlink to ```PaddleGAN/data/``` .
 ```
 python data/download_cyclegan_data.py --name horse2zebra
 ```
 
-#### custom dataset
+#### Custom dataset
 
 Data should be arranged in following way if you use custom dataset.
 
@@ -65,13 +75,15 @@ custom_datasets
 └── trainB
 ```
 
-### Datasets of Pix2Pix
+#### 2.1.2 Datasets of Pix2Pix
+
+- #### Download from website
 
-#### Download from website
 
 Dataset for pix2pix can be downloaded from [here](https://people.eecs.berkeley.edu/~tinghuiz/projects/pix2pix/datasets/)
 
-#### Download by script
+- #### Download by script
+
 
 You can use ```download_pix2pix_data.py``` in ```PaddleGAN/data``` to download datasets you wanted. Supported datasets are: apple2orange, summer2winter_yosemite,horse2zebra, monet2photo, cezanne2photo, ukiyoe2photo, vangogh2photo, maps, cityscapes, facades, iphone2dslr_flower, ae_photos, cityscapes.
 
@@ -82,7 +94,7 @@ python data/download_pix2pix_data.py --name cityscapes
 ```
 
 #### Custom datasets
-Data should be arranged in following way if you use custom dataset. And image content shoubld be same with example image.
+Data should be arranged in following way if you use custom dataset. And image content should be the same with example image.
 
 ```
 facades