Refactor mkdocs.yml to streamline navigation structure

- Removed unnecessary indentation for the "Model Stacking" entry in the navigation.
- Maintained the link to the tutorial notebook "tutorials/16-Model Stacking.ipynb" for user access.

This change improves the clarity of the documentation structure without altering the content.

Author: taimo

mkdocs.yml

@@ -24,8 +24,7 @@ nav:
                 - SHAP, Deep LIFT and so on through Captum Integration: "tutorials/14-Explainability.ipynb"
           - Custom PyTorch Models:
                 - Implementing New Supervised Architectures: "tutorials/04-Implementing New Architectures.ipynb"
-          - Model Stacking:
-                - Model Stacking: "tutorials/16-Model Stacking.ipynb"
+          - Model Stacking: "tutorials/16-Model Stacking.ipynb"
           - Other Features:
                 - Using Neural Categorical Embeddings in Scikit-Learn Workflows: "tutorials/03-Neural Embedding in Scikit-Learn Workflows.ipynb"
                 - Self-Supervised Learning using Denoising Autoencoders: "tutorials/08-Self-Supervised Learning-DAE.ipynb"