Update plugin's description
Update plugin's description

The plugin's description is going to be displayed in the Fuel UI once
the deployment is completed [1]. This change modifies the description
to instruct the end-user what to do next.

[1] https://review.openstack.org/#/c/164256

Change-Id: If20bf781a75cae10275a57efd0dad47d87f666db

stackforge/fuel-plugin-elasticsearch-kibana,stackforge/fuel-plugin-elasticsearch-kibana,stackforge/fuel-plugin-elasticsearch-kibana