I am the plugin author for Joli Table of Contents.
Since my native language is French I have already translated and imported the strings for that specific locale while making sure the translations are relevant to their particular context within the UI. Now they are waiting for approval.
Please add the following WordPress.org user as translation editor:
Link to the plugin :
- https://wordpress.org/plugins/joli-table-of-contents/
If you have any questions, just comment here. Thank you!