Update readme to include how to run examples with docker compose (#73)

* Add black to pre commit hooks

* Update readme to include how to run examples with docker compose

.pre-commit-config.yaml

@@ -25,3 +25,7 @@ repos:
     hooks:
     -   id: pyupgrade
         args: [--py36-plus]
+  - repo: https://github.com/ambv/black
+    rev: 22.6.0
+    hooks:
+      - id: black

README.md

@@ -8,8 +8,8 @@ Brokerless task queue for python based on 0Mq
 ========================
 
 * Configuring Environment Variables:
-    - WORKER_HOST=
-    - WORKER_PORT=
+    - WORKER_HOST          # The IP address to expose running workers on
+    - WORKER_PORT                   # The port number workers should listen on
 
     -- `If not set defaults to localhost:5690`
 
@@ -52,7 +52,51 @@ long_running_task.run(param="dowork")
      - Fast
      - Open source
 
-### Using a container orchestration technology:
+
+### Running Zebrok examples with docker compose
+* First clone the repository using the command `git clone [email protected]:kaypee90/zebrok.git`
+* Change directory into the zebrok directory and run `docker compose up` command to start the worker and publisher containers.
+* Access the shell for the **worker** container and run the command `python examples/start.py` to start the workers.
+* From a different terminal window, access the shell for the running **publisher** container and run the command `python examples/client.py` to queue 2 jobs to be processed.
+* Once these commands are executed you should see 2 tasks processed successfully in the publisher terminal.
+
+
+**Sample output:**
+```
+** 2 ZEBROK TASKS DISCOVERED! 
+=====================================================
+  * long_running_task_one 
+  * long_running_task_two 
+=====================================================
+2023-10-11 23:45:14,227 zebrok.discovery INFO:** 2 ZEBROK TASKS DISCOVERED! 
+=====================================================
+  * long_running_task_one 
+  * long_running_task_two 
+=====================================================
+starting worker on: tcp://172.21.0.3:5691
+2023-10-11 23:45:14,236 zebrok.worker INFO:starting worker on: tcp://172.21.0.3:5691
+starting worker on: tcp://172.21.0.3:5692
+2023-10-11 23:45:14,237 zebrok.worker INFO:starting worker on: tcp://172.21.0.3:5692
+starting worker on: tcp://172.21.0.3:5693
+starting worker on: tcp://172.21.0.3:5690
+2023-10-11 23:45:14,238 zebrok.worker INFO:starting worker on: tcp://172.21.0.3:5693
+2023-10-11 23:45:14,238 zebrok.worker INFO:starting worker on: tcp://172.21.0.3:5690
+sending task to slave worker
+2023-10-11 23:48:07,297 zebrok.worker INFO:sending task to slave worker
+sending task to slave worker
+received task: long_running_task_one
+2023-10-11 23:48:07,299 zebrok.worker INFO:sending task to slave worker
+2023-10-11 23:48:07,299 zebrok.worker INFO:received task: long_running_task_one
+received task: long_running_task_two
+2023-10-11 23:48:07,300 zebrok.worker INFO:received task: long_running_task_two
+Sent mail to, [email protected]
+Hello, Kay Pee
+DONE!!!
+DONE!!!
+```
+
+
+### Using a container orchestration technology (like Kubernetes):
 - `number_of_slaves` must always be set to 0, then you can spin a number of replicas for the workers.
-- `WORKER_HOST`Environment variable for a worker must always be `*`
+- `WORKER_HOST` Environment variable for a worker must always be `*`