Merge pull request #6464 from SvenDowideit/pr_out_exclaimation_marks_cause_shell_pain_simplify_it_away

exclaimation marks cause shell pain - simplify it away

docs/sources/userguide/dockerizing.md

@@ -13,7 +13,7 @@ application inside a container takes a single command: `docker run`.
 
 Let's try it now.
 
-    $ sudo docker run ubuntu:14.04 /bin/echo 'Hello World!'
+    $ sudo docker run ubuntu:14.04 /bin/echo 'Hello World'
     Hello World!
 
 And you just launched your first container!