Update README.md

Author: Ravi Prakash Joshi

lib/README.md

@@ -2,7 +2,8 @@
 Older version of `protobuf` might be installed already. Hence, in order to ignore the conflict, we are using locally install `protobuf`
 
 # Steps
-Place extracted `protobuf-3.5.0.tar.gz` here. The directory structure should look as following:
+1. Download the `protobuf-3.5.0.tar.gz` from release page. The URL of the file is [here](https://github.com/ravijo/ros_protocol_buffer_tutorial/releases/download/1/protobuf-3.5.0.tar.gz)
+1. Place extracted `protobuf-3.5.0.tar.gz` here. The directory structure should look as following:
 
 ```
 lib