Add usage example and requirements to README.md

Author: cjaliaga

README.md

@@ -3,9 +3,63 @@ Aioaquarea
 
 Asynchronous library to control Panasonic Aquarea devices
 
-> :warning: This library is under development!
+## Requirements
 
-Requires Python >= 3.9 and uses asyncio and aiohttp.
+This library requires:
+
+- Python >= 3.9
+- asyncio
+- aiohttp
+
+## Usage
+The library supports the production environment of the Panasonic Aquarea Smart Cloud API and also the Demo environment. One of the main usages of this library is to integrate the Panasonic Aquarea Smart Cloud API with Home Assistant via [home-assistant-aquarea](https://github.com/cjaliaga/home-assistant-aquarea)
+
+Here is a simple example of how to use the library via getting a device object to interact with it:
+
+```python
+from aioaquarea import (
+    Client,
+    AquareaEnvironment,
+    UpdateOperationMode
+)
+
+import aiohttp
+import asyncio
+import logging
+from datetime import timedelta
+
+async def main():
+    async with aiohttp.ClientSession() as session:
+        client = Client(
+            username="USERNAME",
+            password="PASSWORD",
+            session=session,
+            device_direct=True,
+            refresh_login=True,
+            environment=AquareaEnvironment.PRODUCTION,
+        )
+
+        # The library is designed to retrieve a device object and interact with it:
+        devices = await client.get_devices(include_long_id=True)
+
+        # Picking the first device associated with the account:
+        device_info = devices[0]
+
+        device = await client.get_device(
+            device_info=device_info, consumption_refresh_interval=timedelta(minutes=1)
+        )
+
+        # Or the device can also be retrieved by its long id if we know it:
+        device = await client.get_device(
+            device_id="LONG ID", consumption_refresh_interval=timedelta(minutes=1)
+        )
+
+        # Then we can interact with the device:
+        await device.set_mode(UpdateOperationMode.HEAT)
+
+        # The device can automatically refresh its data:
+        await device.refresh_data()
+```
 
 ## Acknowledgements