Update channel definitions
Update channel definitions

Updated the channel definitions to reflect stable.  Created table to ensure consistency with other install pages.
skynet/docs,jdloft/docs,joshix/docs,mischief/coreos-docs,iankronquist/docs,ksmaheshkumar/docs-2,hkjn/docs-1,mjg59/docs,robszumski/docs,michelleN/docs,bq-xiao/docs,atxwebs/docs,ionave/docs,jonboulle/docs,marineam/coreos-docs,endocode/coreos-docs,coreos/docs,wli6/docs