Update README with app wrapper documentation

Co-authored-by: msis <577139+msis@users.noreply.github.com>

Author: Copilot

README.md

@@ -22,3 +22,55 @@ cd python-moos
 python setup.py build
 python setup.py install
 ```
+
+# Usage
+
+python-moos provides two main classes for interacting with MOOS:
+
+## pymoos.comms - Asynchronous Communications
+
+For simple publish/subscribe communication with the MOOSDB:
+
+```python
+import pymoos
+
+comms = pymoos.comms()
+
+def on_connect():
+    return comms.register('MY_VAR', 0)
+
+comms.set_on_connect_callback(on_connect)
+comms.run('localhost', 9000, 'my_client')
+```
+
+See `Documentation/examples/simplecomms.py` for a complete example.
+
+## pymoos.app - MOOS Application Framework
+
+For building full MOOS applications with structured lifecycle callbacks:
+
+```python
+import pymoos
+
+app = pymoos.app()
+
+def on_startup():
+    app.set_app_freq(10.0)  # Hz
+    return True
+
+def on_connect_to_server():
+    return app.register('MY_VAR', 0)
+
+def iterate():
+    # Main application loop
+    return True
+
+app.set_on_start_up_callback(on_startup)
+app.set_on_connect_to_server_callback(on_connect_to_server)
+app.set_iterate_callback(iterate)
+
+app.run('localhost', 9000, 'my_app')
+```
+
+See `Documentation/examples/simpleapp.py` for a complete example.
+