chore: update .env.example and logger.js for improved configuration and logging level management

src/utils/logger.js

@@ -1,9 +1,9 @@
 const winston = require('winston');
 
 const logger = winston.createLogger({
-  level: 'info',
-  format: winston.format.combine(
-    winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
+    level: process.env.LOG_LEVEL || 'info', // Use LOG_LEVEL from env or default to 'info'
+    format: winston.format.combine(
+        winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
     winston.format.printf(info => `${info.timestamp} ${info.level.toUpperCase()}: ${info.message}`)
   ),
   transports: [