improve changelog heading

snd · snd · commit 97c5e86de688 · 2015-03-23T00:42:57.000+01:00
diff --git a/README.md b/README.md
@@ -144,9 +144,9 @@ wildcardPattern.match('subsub.www.google.com');
 // => {sub: 'www', _: ['subsub', 'com']}
 ```
 
-## changelog
+### changelog
 
-### 0.7
+#### 0.7
 
 instead of
 
