Fix formatting for Datadog entry in README

Author: doanbactam

README.md

@@ -59,6 +59,7 @@ Only official program pages are listed.
 |---|---|---|
 | [AWS Activate](https://aws.amazon.com/startups/credits) | AWS | Cloud credits (up to $100k) |
 | [Clerk for Startups](https://clerk.com/startups) | Clerk | Authentication infrastructure credits |
+| [Datadog for Startups|(https://www.datadoghq.com/partner/datadog-for-startups/) | Datadog | A year of free Datadog Pro |
 | [Google Cloud Startup Program](https://cloud.google.com/startup) | Google | Cloud credits and support |
 | [Google Cloud AI Startup Program](https://cloud.google.com/startup/ai) | Google | AI startup credits (up to $350k) |
 | [Microsoft Founders Hub](https://www.microsoft.com/startups) | Microsoft | Azure credits |