feat: add redis integration and environment variables

lib/redis.ts

@@ -0,0 +1,11 @@
+import Redis from 'ioredis'
+
+const globalForRedis = global as unknown as { redis: Redis }
+
+export const redis =
+  globalForRedis.redis ||
+  new Redis(process.env.REDIS_URL || 'redis://localhost:6379', {
+    maxRetriesPerRequest: null,
+  })
+
+if (process.env.NODE_ENV !== 'production') globalForRedis.redis = redis