Using this editor you can create your own stories or modify existing ones. Try it on https://echsecutor.github.io/story_adventure/editor/ . This is a somewhat minimalistic reference implementation. Improvements or better versions of an editor are most welcome as PRs, or just let me know and I will link your tools.
This tool is part of https://github.com/Echsecutor/story_adventure . See there for license, contirbution, etc. This is also the place to open issues.