Documentation/integrations: add link to etcd raft lib users
- [cloudfoundry/cf-release](https://github.com/cloudfoundry/cf-release/tree/master/jobs/etcd)
**Projects using etcd**
-
+- [etcd Raft users](../raft/README.md#notable-users) - projects using etcd's raft library implementation.
- [apache/celix](https://github.com/apache/celix) - an implementation of the OSGi specification adapted to C and C++
- [binocarlos/yoda](https://github.com/binocarlos/yoda) - etcd + ZeroMQ
- [blox/blox](https://github.com/blox/blox) - a collection of open source projects for container management and orchestration with AWS ECS
