feat: add timegpt finetunning (#332)

* feat: add finetuning config to timegpt

* docs: add new class to docs

* feat: add timegpt to funetuning nb

* fix: rm celss

Author: AzulGarza

docs/api/models/foundation/models.md

@@ -30,6 +30,7 @@
     options:
         members:
             - TimeGPT
+            - TimeGPTFinetuningConfig
 
 ::: timecopilot.models.foundation.timesfm
     options: