remove docs about format extensions
remove docs about format extensions

The format extensions concept (adding .json / .xml) is no longer
really a thing. The router supports it, but we only have json
responses, so there is no reason to advertise it.

Change-Id: I07ba13a98ce55c215c6b676b5ff41d7d60babfde

Juniper/nova,jianghuaw/nova,hanlind/nova,jianghuaw/nova,rahulunair/nova,Juniper/nova,rajalokan/nova,vmturbo/nova,mahak/nova,alaski/nova,alaski/nova,klmitch/nova,zhimin711/nova,jianghuaw/nova,mikalstill/nova,phenoxim/nova,cloudbase/nova,mikalstill/nova,Juniper/nova,BeyondTheClouds/nova,cloudbase/nova,bigswitch/nova,gooddata/openstack-nova,BeyondTheClouds/nova,phenoxim/nova,dims/nova,cyx1231st/nova,BeyondTheClouds/nova,gooddata/openstack-nova,cernops/nova,rajalokan/nova,mahak/nova,openstack/nova,vmturbo/nova,gooddata/openstack-nova,CEG-FYP-OpenStack/scheduler,klmitch/nova,vmturbo/nova,zhimin711/nova,vmturbo/nova,NeCTAR-RC/nova,rajalokan/nova,mahak/nova,CEG-FYP-OpenStack/scheduler,cyx1231st/nova,cernops/nova,hanlind/nova,rahulunair/nova,openstack/nova,hanlind/nova,sebrandon1/nova,openstack/nova,jianghuaw/nova,klmitch/nova,rahulunair/nova,sebrandon1/nova,rajalokan/nova,sebrandon1/nova,dims/nova,klmitch/nova,Juniper/nova,mikalstill/nova,bigswitch/nova,NeCTAR-RC/nova,cloudbase/nova,cernops/nova,gooddata/openstack-nova