Planning for {Project} Guide - Content Sources terminology

[jeremylenz]

The "Content Sources" section of the guide talks about the various places from which Katello content can come. I think this should probably be renamed "Sources of content," since we already have two other (unrelated) things that we refer to as content sources:

• Change Content Source - In this context, a "content source" is the Smart Proxy from which a host gets its content. The smart proxy's url is configured in the [server] section of its rhsm.conf subscription-manager configuration. To change the Smart Proxy from which a host gets content, you can use the Change Content Source feature and it will perform both the server-side and client-side steps. This is documented here -> https://docs.theforeman.org/nightly/Managing_Hosts/index-katello.html#Changing_the_Content_Source_of_a_Host_managing-hosts
• Alternate Content Sources - This is a way to redefine the primary location from which Katello syncs content for the repositories under a given product. This is documented here -> https://docs.theforeman.org/nightly/Managing_Content/index-katello.html#Managing_Alternate_Content_Sources_content-management