Update 3.insertionSort.md

LokiSharp · web-flow · commit 06626459852b · 2017-01-22T13:04:50.000+08:00
diff --git a/3.insertionSort.md b/3.insertionSort.md
@@ -48,4 +48,4 @@ def insertionSort(arr):
             preIndex-=1
         arr[preIndex+1] = current
     return arr
-'''
+```
