Update README.md to inform about expo issue

[flx-sta]

PR Creator Checklist

Ensure you've checked the following before submitting your PR:

• [x] You've discussed making your changes with a member of the dev team per contributing rules in the README
• [x] Your changes are free of any lint errors
• [x] Your changes are free of any typescript errors
• [x] You've tested your changes

Summary

updating the readme to represent the current state of using expo to run the app in

Screenshots