Fix backticks in instapy recipe

manuscript/recipes/instapy.md

@@ -75,6 +75,7 @@ services:
 Create a variation of https://github.com/timgrossmann/InstaPy/blob/master/docker_quickstart.py at /var/data/instapy/instapy.py (the file we bind-mounted in the swarm config above)
 
 Change at least the following:
+
 ````
 insta_username = ''
 insta_password = ''