Give information on how we now re-build Ceph from upstream

- Get rid of dist-git sources, this won't be used as a dist-git
  repository anymore but keep the spec file for reference.

README.md

@@ -1,12 +1,31 @@
-This is a dist-git like repo for [Ceph](https://github.com/ceph/ceph).
+CentOS Storage SIG: Ceph Jewel
+==============================
+The [CentOS Storage SIG for Ceph](https://wiki.centos.org/SpecialInterestGroup/Storage/)
+used to maintain a dist-git like repository here in order to package and mirror
+Ceph for the CentOS community.
 
-The master branch is unused. Use an existing branch instead.
-[Branch names](https://wiki.centos.org/BrianStinson/GitBranchesandKojiTags):
+We have since then decided to re-build Ceph from the source RPMs provided
+[straight from upstream](http://download.ceph.com/rpm-jewel/el7/SRPMS/).
 
-* sig-storage7-ceph-hammer : Ceph Hammer (0.94.x) for CentOS 7
-* sig-storage7-ceph-jewel  : Ceph Jewel  (10.2.x) for CentOS 7
+The spec file is kept here and versioned for reference purposes.
 
-Instructions for building the Ceph package for the CentOS Storage SIG can be found in the following places:
+The contents of this repository are still available in the Git source code
+management system.  To see the contents of this repository before we moved
+away from dist-git, please check out the previous commits.
 
-* [Comunity Build System](https://wiki.centos.org/HowTos/CommunityBuildSystem)
-* [Storage SIG landing page](https://wiki.centos.org/SpecialInterestGroup/Storage/)
+Build and tag information
+-------------------------
+Builds for Ceph for CentOS by the storage SIG are done through the
+[Community Build System](https://wiki.centos.org/HowTos/CommunityBuildSystem) (CBS).
+
+You can find the [tags](https://cbs.centos.org/koji/search?match=glob&type=tag&terms=storage7-ceph-jewel*)
+and the [builds](https://cbs.centos.org/koji/packageinfo?packageID=534)
+directly in the CBS interface.
+
+Package and mirror availability
+-------------------------------
+Installing the package **centos-release-ceph-jewel** from CentOS extras will
+provide the stable and testing repositories for the Jewel release of Ceph.
+
+The testing repository is disabled by default but you can enable it to test an
+upcoming release.