Italian/accelerate (#17698)

* Add 'accelerate' to _toctree file

* Fix 'training with a nb' title

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

docs/source/it/_toctree.yml

@@ -15,6 +15,8 @@
     title: Preprocess
   - local: training
     title: Mettere a punto un modello pre-addestrato
+  - local: accelerate
+    title: Allenamento distribuito con 🤗 Accelerate
   - local: model_sharing
     title: Condividere un modello
   title: Esercitazione