Add headers and code snippets to readme

readme.md

@@ -1,5 +1,25 @@
 # Twitch Plays Plotter
 
+A javascript based project with which you can control a pen plotter through the chat of a Twitch livestream.
+
+## Setup
+The channel you connect to is specified with the following lines. No authentication is needed, if you're only reading from the chat.
+```javascript
+const client = new tmi.Client({
+    channels: ['twitchplaysplotter']
+});
+```
+
+The communicative channel with the plotter might depend on your specific plotter and the port it is connected to. This is specified with the following lines:
+```javascript
+const port = new SerialPort({
+    path: '/dev/ttyUSB0',
+    baudRate: 9600,
+})
+```
+
+
+## Supported commands
 The tale of the untested bit of javascript:
 
 the commands are right now