Doc updates for app update chapter

- Fix typo
- Explicit directions for which directory to work in

Author: rddefauw

03-path-application-development/303-app-update/readme.adoc

@@ -16,7 +16,9 @@ For our usecase, the application initially uses the image `arungupta/app-upgrade
 
 This chapter uses a cluster with 3 master nodes and 5 worker nodes as described here: link:../cluster-install#multi-master-multi-node-multi-az-gossip-based-cluster[multi-master, multi-node gossip based cluster].
 
-All configuration files for this chapter are in the `app-udpate` directory. Make sure you change to that directory before giving any commands in this chapter.
+All configuration files for this chapter are in the `app-update` directory. Make sure you change to that directory before giving any commands in this chapter.  If you are working in Cloud9, run:
+
+    cd ~/environment/aws-workshop-for-kubernetes/03-path-application-development/303-app-update/
 
 == Update and Rollback