Update README.md

README.md

@@ -1,4 +1,4 @@
-### Concode dataset
+## Concode dataset
 
 A large dataset with over 100,000 examples consisting of Java classes from online code repositories, and develop a new encoder-decoder architecture that models the interaction between the method documentation and the class environment.
 
@@ -14,7 +14,7 @@ Data statistics of concode dataset are shown in the below table:
 | Validation |    2,000    |
 |    Test    |    2,000    |
 
-### Data Format
+## Data Format
 
 Code corpus are saved in json lines format files. one line is a json object:
 ```