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

_data/tutorials.yml

@@ -58,4 +58,6 @@ toc:
   - title: Running a Single-Instance Stateful Application
     path: /docs/tutorials/stateful-application/run-stateful-application/
   - title: Running a Replicated Stateful Application
-    path: /docs/tutorials/stateful-application/run-replicated-stateful-application/
+    path: /docs/tutorials/stateful-application/run-replicated-stateful-application/
+  - title: Running ZooKeeper, A CP Distributed System
+    path: /docs/tutorials/stateful-application/zookeeper/