Fix broken links in introyt_index.html (#3291)

Author: svekars

beginner_source/introyt/introyt_index.py

@@ -1,11 +1,11 @@
 """
-`Introduction <introyt/introyt1_tutorial.html>`_ ||
-`Tensors <introyt/tensors_deeper_tutorial.html>`_ ||
-`Autograd <introyt/autogradyt_tutorial.html>`_ ||
-`Building Models <introyt/modelsyt_tutorial.html>`_ ||
-`TensorBoard Support <introyt/tensorboardyt_tutorial.html>`_ ||
-`Training Models <introyt/trainingyt.html>`_ ||
-`Model Understanding <introyt/captumyt.html>`_
+`Introduction <introyt1_tutorial.html>`_ ||
+`Tensors <tensors_deeper_tutorial.html>`_ ||
+`Autograd <autogradyt_tutorial.html>`_ ||
+`Building Models <modelsyt_tutorial.html>`_ ||
+`TensorBoard Support <tensorboardyt_tutorial.html>`_ ||
+`Training Models <trainingyt.html>`_ ||
+`Model Understanding <captumyt.html>`_
 
 Introduction to PyTorch - YouTube Series
 ========================================