Update index.rst

Author: svekars

docs/source/index.rst

@@ -31,7 +31,9 @@ Welcome to the ExecuTorch Documentation
    </div>
 
 The ExecuTorch source is hosted on GitHub at
-https://github.com/pytorch/executorch.
+https://github.com/pytorch/executorch. 
+Join us on `Discord <https://discord.com/invite/Dh43CKSAdc>`__ if you have questions
+about ExecuTorch or would like to become a contributor!
 
 Getting Started
 ~~~~~~~~~~~~~~~