README.md added

README.md

+1. Clone this project.
+2. Package war file
+3. Deploy in a tomcat server
+4. Encryption Url: host_url/ekpayencryption/encrypt
+5. Decryption Url: host_url/ekpayencryption/decrypt
+6. use shared SKEY as secretKey (requestParam)
+7. Give plain/cipher text in request body
+
+You can also download WAR using the below link
+   https://drive.google.com/file/d/1G8JZSw8r3rKF6lm5CWnqVmH9CKdHdkoP/view?usp=drive_link
+
+Swagger documentation also available
+
+host_url/ekpayencryption/swagger-ui.html