update readme

README.md

@@ -1,3 +1,29 @@
 DockerFile for invoice ninja (https://www.invoiceninja.com/)
 
-To test Invoice Ninja you can clone this repos and run `docker-compose up`.
+This image is based on `php:7` official version.
+
+The easiest way to try this image is via docker compose :
+
+```
+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
+```

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