Update torchrec_intro_tutorial.py

Author: svekars

intermediate_source/torchrec_intro_tutorial.py

@@ -39,6 +39,12 @@
 #    !pip3 install fbgemm_gpu --index-url https://download.pytorch.org/whl/cu121
 #    !pip3 install torchmetrics==1.0.3
 #    !pip3 install torchrec --index-url https://download.pytorch.org/whl/cu121
+#
+# .. note:: 
+#    If you are running this in Google Colab, make sure to switch to a GPU runtime type.
+#    For more information,
+#    see `Enabling CUDA <https://pytorch.org/tutorials/beginner/colab#enabling-cuda>`__
+#