Improve development tools

[Ahmed Elhanafy]

• Improve ESLint and Prettier
• Streamline Flow usage in the app
• Add storybook
• Improve red screen errors in web dev server
• Improve source maps support

Improve ESLint and Prettier

• Get a decent ESLint config that plays nicely with Prettier
• Run ESLint before committing

Streamline Flow usage in the app

• Fix flow config
• Run Flow before committing

Improve red screen errors in web dev server

• Syntax errors should also appear in the browser instead of the terminal only
• CMD+S should always trigger the app to refresh (hot or cold refresh)
• Try to integrate CRA app red screen