GitLab

* enable optuna multi-objectives feature
Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* Apply suggestions from code review
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* update hpo doc

* update docstring
Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* extend direction to List[str] type
Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* Update src/transformers/integrations/integration_utils.py
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

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Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

Update outdated hyperlink hpo_train.md 

Link to RayTune search space API docs was outdated - have provided correct new link for docs.
Co-authored-by: Joshua Samuel <66880119+Joshsamuel101@users.noreply.github.com>

* Rename index.mdx to index.md

* With saved modifs

* Address review comment

* Treat all files

* .mdx -> .md

* Remove special char

* Update utils/tests_fetcher.py
Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

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Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>
Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* add doc for hyperparameter search

* update doc