Update README

README.md

@@ -1,2 +1,29 @@
 # hello-world-deferred
-Deferred Hello World Docker Image
+Hello World Docker Image with delayed output.
+
+## Usage
+Prints "Hello World!" after 2 seconds.
+```sh
+$ docker run kabirbaidhya/hello-world-deferred
+
+> Hello World!
+```
+
+Defer the output for custom time interval.
+```sh
+$ docker run -e DELAY=10s kabirbaidhya/hello-world-deferred
+
+> Hello World!
+```
+
+Make it verbose.
+```sh
+$ docker run -e DELAY=10s -e VERBOSE=true kabirbaidhya/hello-world-deferred
+
+> Waiting for 5s
+> Hello World!
+```
+
+## License
+Licensed under [MIT License](LICENSE).
+