rename file to have auto play

docs/admin-guide/puppet/puppet_environments.md

@@ -26,7 +26,7 @@ puppet agent -t --environment=issue_x
 
 The following video shows all the necessary steps in detail. (The left terminal is a shell on my workstation, the right terminal is a shell on a test server)
 
-<video controls width="100%" src="./dev_environments.m4v">video</video>
+<video controls width="100%" src="dev_environments.mp4">video</video>
 
 Once you are done with the develoment and testing create a merge request for the branch to the __preprod__ branch.