Made changes per doc conventions to horizon.rst
Made changes per doc conventions to horizon.rst

changed file to comply with official doc conventions
horizon should be lowercase per the official name
and capitalization section in the wiki
documentation conventions for OpenStack
https://wiki.openstack.org/wiki/Documentation/Conventions
Partial-bug: 1446253

Change-Id: Icdec9764535c509432b60ac2b3aee54da40d2085

mdavid/horizon,openstack/horizon,davidcusatis/horizon,j4/horizon,yjxtogo/horizon,coreycb/horizon,django-leonardo/horizon,wolverineav/horizon,saydulk/horizon,takeshineshiro/horizon,doug-fish/horizon,damien-dg/horizon,Metaswitch/horizon,NeCTAR-RC/horizon,FNST-OpenStack/horizon,sandvine/horizon,Hodorable/0602,gerrive/horizon,RudoCris/horizon,redhat-cip/horizon,newrocknj/horizon,vladryk/horizon,mdavid/horizon,NeCTAR-RC/horizon,idjaw/horizon,tqtran7/horizon,tellesnobrega/horizon,ChameleonCloud/horizon,coreycb/horizon,ChameleonCloud/horizon,dan1/horizon-proto,dan1/horizon-proto,karthik-suresh/horizon,django-leonardo/horizon,luhanhan/horizon,saydulk/horizon,davidcusatis/horizon,maestro-hybrid-cloud/horizon,wolverineav/horizon,Tesora/tesora-horizon,kfox1111/horizon,RudoCris/horizon,luhanhan/horizon,django-leonardo/horizon,Tesora/tesora-horizon,wolverineav/horizon,FNST-OpenStack/horizon,idjaw/horizon,tellesnobrega/horizon,wolverineav/horizon,vladryk/horizon,noironetworks/horizon,newrocknj/horizon,Hodorable/0602,Solinea/horizon,liyitest/rr,anthonydillon/horizon,redhat-cip/horizon,Mirantis/mos-horizon,philoniare/horizon,davidcusatis/horizon,agileblaze/OpenStackTwoFactorAuthentication,Solinea/horizon,maestro-hybrid-cloud/horizon,icloudrnd/automation_tools,agileblaze/OpenStackTwoFactorAuthentication,eayunstack/horizon,endorphinl/horizon,luhanhan/horizon,bac/horizon,endorphinl/horizon-fork,eayunstack/horizon,coreycb/horizon,anthonydillon/horizon,liyitest/rr,philoniare/horizon,doug-fish/horizon,mdavid/horizon,redhat-openstack/horizon,yeming233/horizon,karthik-suresh/horizon,dan1/horizon-x509,Solinea/horizon,karthik-suresh/horizon,Mirantis/mos-horizon,damien-dg/horizon,noironetworks/horizon,mandeepdhami/horizon,tellesnobrega/horizon,yjxtogo/horizon,watonyweng/horizon,liyitest/rr,sandvine/horizon,bac/horizon,davidcusatis/horizon,dan1/horizon-x509,liyitest/rr,henaras/horizon,eayunstack/horizon,dan1/horizon-proto,sandvine/horizon,noironetworks/horizon,newrocknj/horizon,Dark-Hacker/horizon,damien-dg/horizon,maestro-hybrid-cloud/horizon,agileblaze/OpenStackTwoFactorAuthentication,yjxtogo/horizon,gerrive/horizon,icloudrnd/automation_tools,RudoCris/horizon,gerrive/horizon,NeCTAR-RC/horizon,j4/horizon,django-leonardo/horizon,mandeepdhami/horizon,vladryk/horizon,dan1/horizon-proto,endorphinl/horizon,bac/horizon,mdavid/horizon,agileblaze/OpenStackTwoFactorAuthentication,tqtran7/horizon,j4/horizon,bac/horizon,icloudrnd/automation_tools,damien-dg/horizon,j4/horizon,Mirantis/mos-horizon,ChameleonCloud/horizon,endorphinl/horizon,anthonydillon/horizon,doug-fish/horizon,BiznetGIO/horizon,kfox1111/horizon,watonyweng/horizon,icloudrnd/automation_tools,sandvine/horizon,redhat-openstack/horizon,kfox1111/horizon,Dark-Hacker/horizon,mandeepdhami/horizon,endorphinl/horizon-fork,idjaw/horizon,idjaw/horizon,Dark-Hacker/horizon,watonyweng/horizon,Tesora/tesora-horizon,mandeepdhami/horizon,bigswitch/horizon,Tesora/tesora-horizon,redhat-openstack/horizon,dan1/horizon-x509,henaras/horizon,BiznetGIO/horizon,xinwu/horizon,takeshineshiro/horizon,xinwu/horizon,bigswitch/horizon,takeshineshiro/horizon,redhat-cip/horizon,henaras/horizon,Mirantis/mos-horizon,bigswitch/horizon,redhat-cip/horizon,FNST-OpenStack/horizon,endorphinl/horizon-fork,FNST-OpenStack/horizon,luhanhan/horizon,NeCTAR-RC/horizon,ChameleonCloud/horizon,endorphinl/horizon-fork,philoniare/horizon,noironetworks/horizon,xinwu/horizon,Metaswitch/horizon,redhat-openstack/horizon,endorphinl/horizon,tqtran7/horizon,bigswitch/horizon,dan1/horizon-x509,xinwu/horizon,Dark-Hacker/horizon,vladryk/horizon,takeshineshiro/horizon,karthik-suresh/horizon,Hodorable/0602,maestro-hybrid-cloud/horizon,Metaswitch/horizon,coreycb/horizon,BiznetGIO/horizon,Solinea/horizon,watonyweng/horizon,doug-fish/horizon,yjxtogo/horizon,tellesnobrega/horizon,BiznetGIO/horizon,RudoCris/horizon,tqtran7/horizon,anthonydillon/horizon,gerrive/horizon,yeming233/horizon,newrocknj/horizon,henaras/horizon,openstack/horizon,yeming233/horizon,kfox1111/horizon,saydulk/horizon,openstack/horizon,openstack/horizon,Metaswitch/horizon,philoniare/horizon,Hodorable/0602,saydulk/horizon,yeming233/horizon