Add readme

README.md

+# rsync
+
+This cronjob rsyncs Fedora and EPEL, among others. Access to the Fedora/EPEL tier1
+mirror network is restricted and the IPs of the machines doing the rsync have to
+be allowed to access. Should the IPs of one of these machines change, you'll get
+"access denied" errors. You'll have to open a ticket to Fedora Infrastructure
+for them to update the IPs. For example:
+
+   * https://pagure.io/fedora-infrastructure/issue/9350
+   * https://pagure.io/fedora-infrastructure/issue/11548