TODO

[ ] If a thumbnail failed to load, delete the previous thumbnail and trigger the generation of a new thumbnail: updat the DB accordingly.
[ ] In the ChapterSelect component, limit the number of thumbnail to display: react-intersection-observer lib (https://medium.com/@She_Daddy/using-the-intersection-observer-api-dbe13144b5da)
[ ] Find a way to limit the panning depending on the zoom level.
[ ] Migrate the whole application to nextjs: enjoy available end point.