Update docker commands for subscriber/publisher containers

examples/kafka-hub/A Guide on implementing Websub Hub backed by Kafka Message Broker.md

@@ -184,6 +184,12 @@ Then execute the below command to run the program.
 BAL_CONFIG_FILES=/path/to/Config.toml bal run target/bin/wbsbsubscriber.jar
 ```
 
+Running the subscriber on docker.
+
+```sh
+docker run --rm --name <name-of-container> -e TOPIC_NAME="<topic-name>" -e CONSUMER_GROUP="<consumer-group>" -e HUB_URL="<hub-URL>" -e UNSUB_ON_SHUTDOWN="true" -e SVC_PORT="<subscriber-port>" --network="<docker-network-name>" --hostname=<hostname> ayeshalmeida/wbsbsubscriber:5.0.0
+```
+
 ## Publishing to the Hub
 
 Go into the `publisher` directory and execute the following command.
@@ -198,6 +204,12 @@ Then execute the below command to run the program.
 BAL_CONFIG_FILES=/path/to/Config.toml bal run target/bin/wbsbpublisher.jar
 ```
 
+Running the publisher on docker.
+
+```sh
+docker run --rm --network host --name websub-publisher -e TOPIC_NAME="<topic-name>" ayeshalmeida/wbsbpublisher:4.0.0
+```
+
 # Scaling the Hub
 The scaling of the hub can be done vertically or horizontally. As the hub itself does not maintain any state, those can be scaled up and down as needed. The entire cluster of hubs can be considered as one unit as in you can publish to a particular hub and consume the update message from another hub.