Add additional environment variables to README

Two new environment variables (ENABLE_TIMING_LOGS and RUST_LOG) have been added to the README.md instructions. These were inserted to refine the project debug process by providing more detailed log information and enabling timing logs.

README.md

@@ -73,6 +73,8 @@ export PORT=8443
 export TLS_CERT_PATH=/path/to/fullchain.pem
 export TLS_KEY_PATH=/path/to/privkey.pem
 export KAS_KEY_PATH=/path/to/recipient_private_key.pem
+export ENABLE_TIMING_LOGS=true
+export RUST_LOG=info
 ```
 
 (Optional) Set the environment variables if you want to override the defaults.