annotating-domain-whitelist

per reedy’s request in https://gerrit.wikimedia.org/r/#/c/101061/9/wmf-config/InitialiseSettings.php,
adding some annotations next to the whitelisted domains in the wgCopyUploadsDomains array.

Change-Id: Ibc337461a46f8e69168e4a664ff6021f8b4fe82e