adding example

Author: jkyberneees

README.md

@@ -1,6 +1,12 @@
 # restana-static
 Efficiently serve static files using Node.js and Docker containers: https://itnext.io/restana-static-serving-the-frontend-with-node-js-beyond-nginx-e45fdb2e49cb
 
+```Dockerfile
+FROM kyberneees/restana-static:latest
+RUN rm dist/index.html
+RUN echo "Hello World!" >> dist/index.html
+```
+
 ## Configuration options
 restana-static image configuration is manage using the module: https://www.npmjs.com/package/config, so developers can manage multiple envirments if desired.