I'd start the Readme with a very clear, concise "what this is, and why it exists/what problems it solves" section. What inspired you to create it? How are you using it? How are others using it? This would be interesting.
I'd either move the "One Packing List App Written in:" section to its own .md and link to it from the Readme, or move it below the "what this is and why" section.
I'd move the Contributors table to its own .md file with a link from the Readme
You don't seem to have a Contributing.md -- are you actively looking for more contributors? If so, I'd add this file and describe how you want people to contribute (here's a good example: https://velero.io/docs/main/start-contributing/)
I'd add a maintainers file so people know who is accountable for the project
would add a changelog.md, a roadmap.md, a code of conduct.md, and adopters.md if you'd like to highlight who's using your project and how. This can inspire others to use it, too.
Finishing up a blog post to go with this repo, I'd love to have some feedback:
https://github.com/GantMan/ReactStateMuseum
I will link to the blog post when it is published, of course!