GitLab

* Reorganize doc for multilingual support

* Fix style

* Style

* Toc trees

* Adapt templates

* update XLMProphetNet link

* update DPR link

* change prophetnet link

* change link MBART

* change link GPT

* update gpt2 link

* ctrl update link

* update Transformer-XL link

* Update Reformer link

* update xlnet link

* bert update link

* udpate albert link

* roberta update link

* update distilbert link

* update convbert link

* update XLM link

* xlm roberta update link

* update Flaubert link

* update electra link

* update funnel transformer and longformer

* bart update link

* pegasus update link

* udpate marianmt link

* t5 update link

* mt5 update link

* Map model_type and doc pages names

* Add script

* Fix typo

* Quality

* Manual check for Auto
Co-authored-by: Lysandre <lysandre.debut@reseau.eseo.fr>

* Convert all tutorials and guides

* Convert all remaining rst to mdx

* Track and fix bad links