If your language is not yet available, it will be easy to do. Create a copy of the file i18n/en.yaml and name it with your language’s shortcode (ex: de.yaml or fr.yaml). After that, open the file in a text editor and translate the strings. See Official Docs for more information.
Example:
- id: featured_post
translation: Featured Posts
- id: featured_post
translation: Postes en vedette