message: Fix code formatting.
  the current docs doesn't format --rm correctly. It is rendered as -rm, which causes the command to fail if copied and pasted:
  image
  this PR fixes that behaviour.
  Risk Level: Low
  Testing: None
diff: @@ -22,7 +22,7 @@ the same configuration.
  A very minimal Envoy configuration that can be used to validate basic plain HTTP
  proxying is available in :repo:`configs/google_com_proxy.v2.yaml`. This is not
  -intended to represent a realistic Envoy deployment.
  +intended to represent a realistic Envoy deployment::
  $ docker pull envoyproxy/envoy:latest
  $ docker run --rm -d -p 10000:10000 envoyproxy/envoy:latest
  