Update insertionsort.md

snippets/insertionsort.md

@@ -1,5 +1,23 @@
-### Insertion Sort
+## Insertion Sort
 
+## Implementation
+```python
+arr = [] # list to sort
+
+
+def insertionsort(arr):
+
+    for i in range(1, len(arr)):
+        key = arr[i]
+        j = i-1
+        while j>=0 and key < arr[j]:
+            arr[j+1] = arr[j]
+            j -= 1
+            arr[j+1] = key
+```
+
+
+### Example
 ```python
 arr = [7,4,9,2,6,3]