doc(README): add a qickstart tutorial

README.md

@@ -15,6 +15,42 @@ At the moment, the following functionality is exposed via REST:
 
 and [many more](https://bbernhard.github.io/signal-cli-rest-api/)
 
+
+## Getting started
+
+1. Create a directory for the configuration
+This allows you to update `signal-cli-rest-api` by just deleting and recreating the container without the need to re-register your signal number
+
+```bash
+$ mkdir $HOME/.local/share/signal-cli
+```
+
+
+2. Start a container
+
+```bash
+$ sudo docker run -d --name signal-api --restart=always -p 8080:8080 \
+      -v $HOME/.local/share/signal-cli:/home/.local/share/signal-cli \
+      -e 'MODE=native' bbernhard/signal-cli-rest-api
+```
+
+3. Register or Link you Signal Number
+
+In this case we'll register our container as secondary device, assuming that you already have your primary number running / assigned to your mobile. 
+
+Therefore open http://localhost:8080/v1/qrcodelink?device_name=signal-api in your browser, open Signal on your mobile phone, Go to _Settings > Linked devices_ and scan the QR code using the _+_ button.
+
+4. Test your new REST API
+
+Call the REST api endpoint and send a test message: Replace `+4412345` with your signal number in international number format, and `+44987654` with the recipients number
+
+```bash
+$ curl -X POST -H "Content-Type: application/json" 'http://localhost:8080/v2/send' \
+     -d '{"message": "Test via Signal API!", "number": "+4412345", "recipients": [ "+44987654" ]}' 
+```
+
+You should now have send a message to `+44987654`.
+
 ## Execution Modes 
 
 The `signal-cli-rest-api` supports three different modes of execution, which can be controlled by setting the `MODE` environment variable.