updates

Author: luisaFelixSalles

doc/source/user_guide/tutorials/03-processing_basics/index.rst

@@ -39,4 +39,10 @@ If you are not familiarized with those concepts you can check our concepts secti
        This tutorial demonstrate a basic post-processing procedure
        using PyDPf-Core based on its usual main steps. The goal is to
        transform simulation data into output data that can be used to
-       visualize and analyze simulation results.
+       visualize and analyze simulation results.
+
+.. toctree::
+    :maxdepth: 2
+    :hidden:
+
+    01-main-steps.rst