add docker compose to easily make mongodb container

.env.example

@@ -20,6 +20,13 @@ DATABASE_URL="file:./db.sqlite"
 # NEXTAUTH_SECRET=""
 NEXTAUTH_URL="http://localhost:3000"
 
+# MongoDB
+# mongo DB details
+MONGO_DATABASE=
+DATABASE_URL=
+MONGO_ROOT_USERNAME=
+MONGO_ROOT_PASSWORD=
+
 # Next Auth Discord Provider
 DISCORD_CLIENT_ID=""
 DISCORD_CLIENT_SECRET=""