Updated doc with 'iso' disk_format.
Updated doc with 'iso' disk_format.

akash1808/glance,rickerc/glance_audit,klmitch/glance,citrix-openstack-build/glance,rajalokan/glance,wkoathp/glance,kfwang/Glance-OVA-OVF,ozamiatin/glance,cloudbau/glance,vuntz/glance,sigmavirus24/glance,dims/glance,ntt-sic/glance,wkoathp/glance,stevelle/glance,redhat-openstack/glance,klmitch/glance,tanglei528/glance,darren-wang/gl,akash1808/glance,saeki-masaki/glance,rickerc/glance_audit,SUSE-Cloud/glance,dims/glance,saeki-masaki/glance,ntt-sic/glance,vuntz/glance,cloudbau/glance,rajalokan/glance,JioCloud/glance,takeshineshiro/glance,takeshineshiro/glance,jumpstarter-io/glance,stevelle/glance,redhat-openstack/glance,citrix-openstack-build/glance,sigmavirus24/glance,openstack/glance,openstack/glance,ozamiatin/glance,darren-wang/gl,paramite/glance,scripnichenko/glance,tanglei528/glance,paramite/glance,SUSE-Cloud/glance,kfwang/Glance-OVA-OVF,scripnichenko/glance,jumpstarter-io/glance,JioCloud/glance,openstack/glance