Add reference to release process

README.md

@@ -35,6 +35,7 @@ Documentation
 * [monitoring](https://github.com/grafana/carbon-relay-ng/blob/master/docs/monitoring.md)
 * [TCP admin interface](https://github.com/grafana/carbon-relay-ng/blob/master/docs/tcp-admin-interface.md)
 * [current changelog](https://github.com/grafana/carbon-relay-ng/blob/master/CHANGELOG.md) and [official releasess](https://github.com/grafana/carbon-relay-ng/releases)
+  * [release process](https://github.com/grafana/carbon-relay-ng/blob/master/docs/installation-building.md#release-process)
 * [limitations](https://github.com/grafana/carbon-relay-ng/blob/master/docs/limitations.md)
 * [installation and building](https://github.com/grafana/carbon-relay-ng/blob/master/docs/installation-building.md)
 * [Deploying on Kubernetes](https://github.com/grafana/carbon-relay-ng/blob/master/docs/deploying-on-k8s.md)