[fix] Editing large courses should be much faster

neoncube

Hi everyone! 🙂

Previously, if a course had a lot of words, it would often lag severely when editing the course. This should now be fixed, so it should now be possible to edit large courses! 🙂

Thanks to @nickelelr for reminding me to fix this: https://forum.mylittlewordland.com/d/6654-5000-most-common-french-words/8 🙂