Update documentation with more examples

Update the documentation with more examples of running playbooks,
including how to target a specific vm and force an update of the
COmanage Registry services stack file.

README.md

@@ -133,6 +133,31 @@ been provisioned:
 ansible-playbook training_nodes.yml --tags training_nodes
 ```
 
+To get a list of inventory after provisioning (helpful to obtain mappings
+to use with --limit to target specific nodes):
+
+```
+ansible-inventory --list
+```
+
+To reconfigure one specific node, for example
+
+```
+ansible-playbook \
+    training_nodes.yml \
+    --tags training_nodes \
+    --limt tag_public_fqdn_registry16_comanage_incommon_training
+```
+
+To force an update of the COmanage Registry services stack file:
+
+```
+ansible-playbook \
+    training_nodes.yml \
+    --tags update_stack_file \
+    -e force_update_stack_file=yes
+```
+
 ## SSH Access
 
 Trainers may use their provisioned SSH keys to access all nodes. Each trainer