Update README

README.md

@@ -1,3 +1,54 @@
 # Emmett-Prometheus
 
 Emmett-Prometheus is an [Emmett framework](https://emmett.sh) extension integrating [prometheus](https://prometheus.io) client.
+
+[![pip version](https://img.shields.io/pypi/v/emmett-prometheus.svg?style=flat)](https://pypi.python.org/pypi/emmett-prometheus) 
+
+## Installation
+
+You can install Emmett-Prometheus using pip:
+
+    pip install emmett-prometheus
+
+And add it to your Emmett application:
+
+```python
+from emmett_prometheus import Prometheus
+
+app.use_extension(Prometheus)
+```
+
+## Configuration
+
+Here is the complete list of parameters of the extension configuration:
+
+| param | default | description |
+| --- | --- | --- |
+| auto\_load | `True` | Automatically inject extension on routes and expose metrics |
+| enable\_http\_metrics | `True` | Enable metrics collection on HTTP routes |
+| enable\_ws\_metrics | `True` | Enable metrics collection on Websocket routes |
+| enable\_sys\_metrics | `False` | Enable default Prometheus client system metrics collection |
+| metrics\_route\_path | /metrics | Path for metrics route |
+| metrics\_route\_hostname | | Hostname for metrics route |
+
+You also have some additional customisations available (here we show the defaults):
+
+```python
+app.config.Prometheus.http_histogram_statuses = [200, 201]
+app.config.Prometheus.http_histogram_exclude_methods = ["OPTIONS"]
+app.config.Prometheus.http_histogram_buckets = [
+    5, 35, 100, 200, 500, 1000, "INF"
+]
+app.config.Prometheus.exclude_routes = []
+app.config.Prometheus.metrics_names={
+    "http_counter": "emmett_request_count",
+    "http_histogram": "emmett_request_latency",
+    "ws_gauge": "emmett_websocket_gauge",
+    "ws_recv_counter": "emmett_websocket_messages_recv_count",
+    "ws_send_counter": "emmett_websocket_messages_send_count"
+}
+```
+
+## License
+
+Emmett-prometheus is released under BSD license.