Google have just launched Web Stories WordPress plugin in the WordPress plugin repository. The plugin allow editors to create content in the web stories format from your WordPress website. The plugin was previously available at GitHub as a beta version, it is now available as a full WordPress plugin version 1.0.0.
First question that comes to mind: How hard is it to build a web story from scratch in a text editor?
Not obvious at all, there is the AMP format which could be automated but that's totally different format from Web stories.