Filling the README

Added an how to use and Upcoming features to the readme.

README.md

@@ -1,2 +1,30 @@
 # miniupnp-script
 A script to use miniupnpc to setup port forwarding for a homeserver
+
+## How to use ?
+Fill in the configuration file : `config.yaml`. An example config is provided as `config.example.yaml`.
+
+To declare a port forwarding use the following syntax:
+```yaml
+service-name:
+  internal_port: 1234
+  external_port: 5678
+  protocol: 'TCP'
+```
+
+Once the config is filled accordingly you can execute the script with 
+```bash
+python3 port-forwarder.py
+```
+
+## Upcoming features
+- Possibility to choose to activate one by one the services. Like:
+```
+OPEN 1234 -> 5678 by TCP for service-name ? (y/N)
+```
+- Possibilty to choose to close one by one the services. Like: 
+```
+CLOSE 1234 -> 5678 by TCP for service-name ? (y/N)
+```
+- A `-y` to say yes to all
+- Have a list of the UPnP forwarding opened by the script