Update README.md

Author: igorsgm

README.md

@@ -258,13 +258,13 @@ return [
 
 The class structure of the `pre-push` hooks is the same as the `post-commit` hook shown right above, but implementing `\Igorsgm\GitHooks\Contracts\PrePushHook` interface.
 
-### Testing
+## Testing
 
 ``` bash
 composer test
 ```
 
-### Changelog
+## Changelog
 
 Please see [CHANGELOG](CHANGELOG.md) for more information what has changed recently.