CLI could initialize the scaffolding for releasing React libs

Description

Releasing open source React components requires heavy scaffolding. Once we are done with tests, CI, and examples for react-idle, we could use that setup for other similar projects

React Idle setup is somewhat opinionated but to a reasonable degree. For instance:

• Flow is set up. Not all projects require flow, but having type safety in an open source project is extremely helpful
• code formatting with eslint and prettier should stay there, but tweaks are possible
• rollup is used over webpack, which may introduce a learning curve. Still, rollup has certain advantages for libraries, which was also heavily researched by React team
• testing suite may prove to be too specific, but we'll see that it's reasonable enough
• we like to work with different CIs and will need to pick one

This may require a separate repo. It would be interesting to create something like create-react-app so it can be maintained from one place

Empieza revisando la configuración existente de react-idle, incluidos sus tests, la configuración de CI, los ejemplos, el uso de Flow y la configuración de ESLint y Rollup. Compara esa configuración con la CLI propuesta al estilo de create-react-app y decide si el scaffold debe pertenecer a este repositorio o a otro separado. Se considera terminado cuando estén claramente definidos el scaffold compatible, la elección de CI y el alcance de los valores predeterminados reutilizables.