Adds zookeeper example (#1894)

* Initial commit

* Adds section for cleanup
Corrects some spelling errors
decapitalizes liveness and readiness

* Adds test for zookeeper example

* Address enisoc review

* Remove space between shell and raw annotation

* Remove extranous inserted text

* Remove fencing statement

* Modify sentence for grammer

* refocus to zookeeper with some loss of generality

* Spelling, Grammar, DNS link

* update to address foxish comments

docs/tutorials/index.md

@@ -26,6 +26,8 @@ each of which has a sequence of steps.
 
 * [Running a Replicated Stateful Application](/docs/tutorials/stateful-application/run-replicated-stateful-application/)
 
+* [Running ZooKeeper, A CP Distributed System](/docs/tutorials/stateful-application/zookeeper/)
+
 ### What's next
 
 If you would like to write a tutorial, see