Update README to include a usage example

README.md

@@ -8,6 +8,46 @@ A *simple* token bucket implementation.
 token bucket library. [Simple is better than
 complex](https://peps.python.org/pep-0020/).
 
+## Installation
+
+`simple-token-bucket` is available on PyPI:
+
+```
+python -m pip install simple-token-bucket[redis]
+```
+
+This project requires Python 3.8 or newer to run.
+
+## Usage example
+
+```python
+from simple_token_bucket import SimpleTokenBucket
+from simple_token_bucket.backends.redis import RedisBackend
+
+# Create a new bucket
+third_party_api_rate_limit_bucket = SimpleTokenBucket(
+    name="third_party_api",
+    bucket_size=3,
+    interval=10,
+)
+
+third_party_api_rate_limit_bucket.try_get_token()
+third_party_api_rate_limit_bucket.try_get_token()
+third_party_api_rate_limit_bucket.try_get_token()
+
+# will raises a NotEnoughTokens exception.
+third_party_api_rate_limit_bucket.try_get_token()
+
+# after 10 seconds everything works again.
+import time
+time.sleep(10)
+third_party_api_rate_limit_bucket.try_get_token()
+```
+
+The latest documentation can be found here
+
+> https://simple-token-bucket.readthedocs.io/en/latest/
+
 ## Contributing
 
 Contributions are welcome. See Contributing section in docs.