update readme

docker-compose.yml

@@ -1,21 +0,0 @@
-db:
-  image: mysql
-  environment:
-    MYSQL_DATABASE: ninja
-    MYSQL_ROOT_PASSWORD: mdp
-
-app:
-  image: invoiceninja/invoiceninja
-  links:
-    - db:mysql
-
-web:
-  image: nginx
-  volumes:
-    - ./nginx.conf:/etc/nginx/nginx.conf:ro
-  links:
-    - app
-  volumes_from:
-    - app
-  ports:
-    - 80