Updated modified part in problem 2

Made it show line number
Changed from shell code block to python code block

README.md

@@ -63,10 +63,14 @@ This is a project implementing the blog post by Mbithe Nzomo.
 	**Solution(for now):**
 	Modify line 189 in `fields.py` from
 
-	```shell
-	cls, key = identity_key(instance=obj)
+	```python
+	188 def get_pk_from_identity(obj):
+	189 	cls, key = identity_key(instance=obj)
+	190 	return ':'.join(text_type(x) for x in key)
 	```
 	to
-	```shell
-	cls, key = identity_key(instance=obj)[:2]
+	```python
+	188 def get_pk_from_identity(obj):
+	189 	cls, key = identity_key(instance=obj)[:2]
+	190 	return ':'.join(text_type(x) for x in key)
 	```