feat: Add encode and decode messages in decoder.js

This commit adds the functionality to encode and decode messages in the decoder.js file. It includes the addition of the `encodeMessage` and `decodeMessage` variables, which respectively encode and decode the message "Code by ybtuti". This enhancement improves the functionality of the project by providing the capability to encode and decode messages.

Author: 0xodus-eth

decoder.js

@@ -12,4 +12,6 @@ function decode(encodedStr) {
         }
     }
     return decoded
-}
+}
+const encodeMessage = encode("Code by ybtuti");
+const decodeMessage = decode(encodeMessage);