Update README.md (#4860)

typo fix

README.md

 - (November 20, 2020)
   [How Eidos-Montréal created Grid Sensors to improve observations for training agents](https://blogs.unity3d.com/2020/11/20/how-eidos-montreal-created-grid-sensors-to-improve-observations-for-training-agents/)
 - (November 11, 2020)
-  [2020 AI@Unity interns shoutout]https://blogs.unity3d.com/2020/11/11/2020-aiunity-interns-shoutout/)
+  [2020 AI@Unity interns shoutout](https://blogs.unity3d.com/2020/11/11/2020-aiunity-interns-shoutout/)
 - (May 12, 2020)
   [Announcing ML-Agents Unity Package v1.0!](https://blogs.unity3d.com/2020/05/12/announcing-ml-agents-unity-package-v1-0/)
 - (February 28, 2020)