docs: Enhance documentation and code structure

- Added a new tutorial path for warmstart in tutorials.rst.
- Removed outdated example links from constraint.rst and loss.rst.
- Improved the organization of loss function descriptions in loss.rst, including clearer sections for classification and regression losses.
- Updated example links for various loss functions to point to the correct notebooks.
- Refactored import order in _sklearn_mixin.py for consistency.
- Enhanced docstrings in the plq_Ridge_Classifier and plq_ElasticNet_Classifier classes for better clarity.
- Cleaned up code formatting and removed unnecessary whitespace in _sklearn_mixin.py.

Author: statmlben

doc/source/_examples_toctree.rst

@@ -0,0 +1,27 @@
+:orphan:
+
+.. toctree::
+   :hidden:
+
+   examples/QR.ipynb
+   examples/QR_eps.ipynb
+   examples/CQR.ipynb
+   examples/SVM.ipynb
+   examples/FairSVM.ipynb
+   examples/SVR.ipynb
+   examples/RankRegression.ipynb
+   examples/Path_solution.ipynb
+   examples/Warm_start.ipynb
+   examples/Sklearn_Mixin.ipynb
+   examples/Multiclass_Classification.ipynb
+   examples/NMF.ipynb
+   examples/Smooth_SVM.ipynb
+   examples/MonotonicSVM.ipynb
+   examples/Squared_SVM.ipynb
+   examples/Huber.ipynb
+   examples/MAE.ipynb
+   examples/MSE.ipynb
+   examples/CustomQR.ipynb
+   examples/GridSearchCV_SVM_losses.ipynb
+   examples/GridSearchCV_reg_losses.ipynb
+   examples/ElasticNet.ipynb

doc/source/example.rst

@@ -21,57 +21,14 @@ Example Gallery
    examples/Multiclass_Classification.ipynb
    examples/NMF.ipynb
 
-   examples/Smooth_SVM_new.ipynb
+   examples/Smooth_SVM.ipynb
    examples/MonotonicSVM.ipynb
-   examples/SVM_new.ipynb
-   examples/Squared_SVM_new.ipynb
-   examples/QR_new.ipynb
-   examples/QR_eps_new.ipynb
-   examples/Huber_new.ipynb
-   examples/SVR_new.ipynb
-   examples/MAE_new.ipynb
-   examples/MSE_new.ipynb
-   examples/FairSVM_new.ipynb
+   examples/Squared_SVM.ipynb
+   examples/Huber.ipynb
+   examples/MAE.ipynb
+   examples/MSE.ipynb
    examples/CustomQR.ipynb
    examples/GridSearchCV_SVM_losses.ipynb
    examples/GridSearchCV_reg_losses.ipynb
 
    examples/ElasticNet.ipynb
-main
-
-List of Examples
-----------------
-
-.. toctree::
-   :maxdepth: 1
-
-   examples/QR.ipynb
-   examples/QR_eps.ipynb
-   examples/CQR.ipynb
-   examples/SVM.ipynb
-   examples/FairSVM.ipynb
-   examples/SVR.ipynb
-   examples/RankRegression.ipynb
-   examples/Path_solution.ipynb
-   examples/Warm_start.ipynb
-   examples/Sklearn_Mixin.ipynb
-   examples/Multiclass_Classification.ipynb
-   examples/NMF.ipynb
-
-   examples/Smooth_SVM_new.ipynb
-   examples/MonotonicSVM.ipynb
-   examples/SVM_new.ipynb
-   examples/Squared_SVM_new.ipynb
-   examples/QR_new.ipynb
-   examples/QR_eps_new.ipynb
-   examples/Huber_new.ipynb
-   examples/SVR_new.ipynb
-   examples/MAE_new.ipynb
-   examples/MSE_new.ipynb
-   examples/FairSVM_new.ipynb
-   examples/CustomQR.ipynb
-   examples/GridSearchCV_SVM_losses.ipynb
-   examples/GridSearchCV_reg_losses.ipynb
-   
-   examples/ElasticNet.ipynb
-main