Update doc/README.md

doc/README.md

@@ -20,7 +20,16 @@ Now you are able to open a new terminal:
 
 ![alt text](./assets/new_terminal.png)
 
-# Start the Server:
+# Install packages
+
+First you should install all related packages with
+
+```npm install```
+
+This will install the packages defined in [package.json](../package.json)
+
+# Start the Server
+
 ```npm run devStart``` or ```npx nodemon```
 
 ![alt text](./assets/start_node_server.png)