Provide some examples of running sytest with worker mode synapse (#862)

docker/README.md

@@ -55,10 +55,43 @@ Synapse:
  * `BLACKLIST`: set non-empty to change the default blacklist file to the
    specified path relative to the Synapse directory
 
+Some examples of running Synapse in different configurations:
+
+* Running Synapse in worker mode using
+[TCP-replication](https://github.com/matrix-org/synapse/blob/master/docs/tcp_replication.md):
+
+  ```
+  docker run --rm -it -e POSTGRES=1 -e WORKERS=1 -v /path/to/synapse\:/src:ro \
+      -v /path/to/where/you/want/logs\:/logs matrixdotorg/sytest-synapse:py35
+  ```
+
+* Running Synapse in worker mode using redis:
+
+  ```
+  docker network create testfoobar
+  docker run --network testfoobar --name testredis -d redis:5.0
+  docker run --network testfoobar --rm -it -e POSTGRES=1 -e WORKERS=1 \
+       -v /path/to/synapse\:/src:ro \
+       -v /path/to/where/you/want/logs\:/logs \
+       matrixdotorg/sytest-synapse:py35 --redis-host testredis
+  # Use `docker start/stop testredis` if you want to explicitly kill redis or start it again after reboot
+  ```
+
 Dendrite:
 
 Dendrite does not currently make use of any environment variables.
 
+## Using the local checkout of Sytest
+
+If you would like to run tests with a custom checkout of Sytest, add a volume
+to the docker command mounting the checkout to the `/sytest` folder in the
+container:
+
+```
+docker run --rm -it /path/to/synapse\:/src:ro -v /path/to/where/you/want/logs\:/logs \
+    -v /path/to/code/sytest\:/sytest:ro matrixdotorg/sytest-synapse:py35
+```
+
 ## Building the containers
 
 The containers are built by executing `./build.sh`. You will then have to push