feat: add complete optimizer docs (#3017) [skip ci]

* feat: add complete optimizer docs

* fix: deprecate old torchao adamw low bit

_quarto.yml

@@ -274,6 +274,7 @@ website:
             - docs/dataset_preprocessing.qmd
             - docs/multipack.qmd
             - docs/mixed_precision.qmd
+            - docs/optimizers.qmd
 
         - section: "Advanced Features"
           contents:
@@ -284,7 +285,6 @@ website:
             - docs/sequence_parallelism.qmd
             - docs/gradient_checkpointing.qmd
             - docs/nd_parallelism.qmd
-            - docs/optimizers.qmd
 
         - section: "Troubleshooting"
           contents: