feat(*): Add winston for logging

index.js

@@ -1,7 +1,32 @@
 const Discord = require('discord.js');
+const winston = require('winston');
 const config = require('./config.json');
 const client = new Discord.Client();
 
+const logger = winston.createLogger({
+  level: 'info',
+  format: winston.format.json(),
+  defaultMeta: { service: 'user-service' },
+  transports: [
+    //
+    // - Write all logs with level `error` and below to `error.log`
+    // - Write all logs with level `info` and below to `combined.log`
+    //
+    new winston.transports.File({ filename: 'error.log', level: 'error' }),
+    new winston.transports.File({ filename: 'combined.log' }),
+  ],
+});
+
+//
+// If we're not in production then log to the `console` with the format:
+// `${info.level}: ${info.message} JSON.stringify({ ...rest }) `
+//
+if (process.env.NODE_ENV !== 'production') {
+  logger.add(new winston.transports.Console({
+    format: winston.format.simple(),
+  }));
+}
+
 const queueTitle = '===== QUEUE =====';
 
 let playerQueue = [];