Warning message when 00_Boilerplate project runs

[lagp]

Describe the bug

A warning message appears when you run npm start on 00_Boilerplate project:

`$ npm start

react-typescript-by-sample@1.0.0 start C:\Users\l.garcia\Documents\Repos\React\react-typescript-samples\hooks\00_BoilerPlate
webpack-dev-server --mode development --inline --hot --open

i ｢wds｣: Project is running at http://localhost:8080/
i ｢wds｣: webpack output is served from /
i ｢wds｣: Content not from webpack is served from ./dist
i ｢atl｣: Using typescript@3.6.2 from typescript
i ｢atl｣: Using tsconfig.json from C:/Users/l.garcia/Documents/Repos/React/react-typescript-samples/hooks/00_BoilerPlate/tsconfig.json

WARNING: We noticed you're using the useBuiltIns option without declaring a core-js version. Currently, we assume version 2.x when no version is passed. Since this default version will likely change in future versions of Babel, we recommend explicitly setting the core-js version you are using via the corejs option.

You should also be sure that the version you pass to the corejs option matches the version specified in your package.json's dependencies section. If it doesn't, you need to run one of the following commands:

npm install --save core-js@2 npm install --save core-js@3
yarn add core-js@2 yarn add core-js@3

i ｢wdm｣: wait until bundle finished: /
i ｢atl｣: Checking started in a separate process...
i ｢atl｣: Time: 845ms
i ｢wdm｣: Compiled successfully.`

To Reproduce
Steps to reproduce the behaviour:

1. Go to 00_BoilerPlate directory.
2. Run npm start.

Possible solution

According to core-js@3, babel and a look into the future, we have to specify 'core-js' version when we use the babel option 'useBuiltIns`.