[End User guide] QuickStart, delete app
[End User guide] QuickStart, delete app

Adds the instructions on how to delete an application for the
Quickstart

Change-Id: I166e45e480ca5159cfe8e9696941c356eaa0f180

NeCTAR-RC/murano,olivierlemasle/murano,NeCTAR-RC/murano,DavidPurcell/murano_temp,sajuptpm/murano,DavidPurcell/murano_temp,NeCTAR-RC/murano,DavidPurcell/murano_temp,openstack/murano,satish-avninetworks/murano,olivierlemasle/murano,satish-avninetworks/murano,olivierlemasle/murano,NeCTAR-RC/murano,olivierlemasle/murano,sajuptpm/murano,satish-avninetworks/murano,DavidPurcell/murano_temp,satish-avninetworks/murano,openstack/murano