Add dockerfile, small fixes

src/index.ts

@@ -6,7 +6,7 @@ import app from "./server";
   const DB_URI = process.env.DB_URI ?? "";
 
   await mongoose.connect(DB_URI);
-  await app.listen({ port: PORT });
+  await app.listen({ port: PORT, host: "0.0.0.0" });
 })().catch((err) => {
   console.log(err);
   process.exit(1);