update quickstart docker-compose example, add to release instructions (#10527)

* update quickstart docker-compose example, add to release instructions

* adjust

* spelling
diff --git a/distribution/asf-release-process-guide.md b/distribution/asf-release-process-guide.md
index 61b494b..041d65d 100644
--- a/distribution/asf-release-process-guide.md
+++ b/distribution/asf-release-process-guide.md
@@ -59,7 +59,17 @@
 <script src="public/web-console-0.18.0.js"></script>
 ```
 
-and open a PR to the master branch.
+Finally, the sample [`docker-compose.yml`](https://github.com/apache/druid/blob/master/distribution/docker/docker-compose.yml) used in the Docker quickstart documentation should be updated to reflect the version for the next release:
+
+```yaml
+...
+  coordinator:
+    image: apache/druid:0.18.0
+    container_name: coordinator
+...
+```
+
+Once this is completed, open a PR to the master branch. Also, be sure to confirm that these versions are all correct in the release branch, otherwise fix them and open a backport PR to the release branch.
 
 ### Release branch hygiene
 
diff --git a/distribution/docker/docker-compose.yml b/distribution/docker/docker-compose.yml
index 6a1ee3d..00ff697 100644
--- a/distribution/docker/docker-compose.yml
+++ b/distribution/docker/docker-compose.yml
@@ -46,7 +46,7 @@
       - ZOO_MY_ID=1
 
   coordinator:
-    image: apache/druid:0.17.0
+    image: apache/druid:0.20.0
     container_name: coordinator
     volumes:
       - ./storage:/opt/data
@@ -62,7 +62,7 @@
       - environment
 
   broker:
-    image: apache/druid:0.17.0
+    image: apache/druid:0.20.0
     container_name: broker
     volumes:
       - broker_var:/opt/druid/var
@@ -78,7 +78,7 @@
       - environment
 
   historical:
-    image: apache/druid:0.17.0
+    image: apache/druid:0.20.0
     container_name: historical
     volumes:
       - ./storage:/opt/data
@@ -95,7 +95,7 @@
       - environment
 
   middlemanager:
-    image: apache/druid:0.17.0
+    image: apache/druid:0.20.0
     container_name: middlemanager
     volumes:
       - ./storage:/opt/data
@@ -112,7 +112,7 @@
       - environment
 
   router:
-    image: apache/druid:0.17.0
+    image: apache/druid:0.20.0
     container_name: router
     volumes:
       - router_var:/opt/druid/var
diff --git a/docs/tutorials/docker.md b/docs/tutorials/docker.md
index 2f609ea..33dc8e7 100644
--- a/docs/tutorials/docker.md
+++ b/docs/tutorials/docker.md
@@ -32,11 +32,11 @@
 
 ## Getting started
 
-The Druid source code contains [an example `docker-compose.yml`](https://github.com/apache/druid/blob/master/distribution/docker/docker-compose.yml) which can pull an image from Docker Hub and is suited to be used as an example environment and to experiment with Docker based Druid configuration and deployments.
+The Druid source code contains [an example `docker-compose.yml`](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/docker-compose.yml) which can pull an image from Docker Hub and is suited to be used as an example environment and to experiment with Docker based Druid configuration and deployments.
 
 ### Compose file
 
-The example `docker-compose.yml` will create a container for each Druid service, as well as Zookeeper and a PostgreSQL container as the metadata store. Deep storage will be a local directory, by default configured as `./storage` relative to your `docker-compose.yml` file, and will be mounted as `/opt/data` and shared between Druid containers which require access to deep storage. The Druid containers are configured via an [environment file](https://github.com/apache/druid/blob/master/distribution/docker/environment).
+The example `docker-compose.yml` will create a container for each Druid service, as well as Zookeeper and a PostgreSQL container as the metadata store. Deep storage will be a local directory, by default configured as `./storage` relative to your `docker-compose.yml` file, and will be mounted as `/opt/data` and shared between Druid containers which require access to deep storage. The Druid containers are configured via an [environment file](https://github.com/apache/druid/blob/{{DRUIDVERSION}}/distribution/docker/environment).
 
 ### Configuration