[DOC] Use of French and English in the documentation /docs

[pie-leroy]

At the following URL: https://evalap.etalab.gouv.fr/doc/fr/docs

In “French” mode, the main menus are in English (“Getting Started”) and the submenus are in French (“Installation avec Docker”).

[dtrckd]

I am not sure how to do it with docusaurus atm. It seems that it is a limitation of the framework (side menu + foot menu labels) : facebook/docusaurus#8996

@benjaminpilia

[dtrckd]

Maybe here is a solution to try : https://stackoverflow.com/a/70996504/4223749