feat: Update theory section with missing topics and remove unused files

src/_quarto.yml

@@ -63,23 +63,7 @@ website:
             text: "Perplexity and Quantization"
           - href: theory/regularization.qmd
             text: "Regularization"
-          - section: "Training"
-            href: theory/training.qmd
-            contents:
-            - href: theory/training.qmd
-              text: "Training"
-            - href: theory/dying_neurons.qmd
-              text: "Dying Neurons"
-            - href: theory/overfitting.qmd
-              text: "Overfitting"
-            - href: theory/underfitting.qmd
-              text: "Underfitting"
-            - href: theory/hyperparameter_tuning.qmd
-              text: "Hyperparameter Tuning"
-            - href: theory/transfer_learning.qmd
-              text: "Transfer Learning"
-            - href: theory/early_stopping.qmd
-              text: "Early Stopping"
+
 
           - href: theory/perplexity_in_ai.qmd
             text: "Perplexity and Quantization"