Configuring ESLint

- [Instructor] The first order of business…is to bring in some ESLint configuration.…If I forget a comma here,…or actually leave something that is not used,…I'd like ESLint to be configured…to tell me about these problems when I save this file.…Right now, there is no ESLint configured,…so you can install ESLint…and bring in any configuration you like.…I like to use my own slightly-modified…recommended configuration for ESLint,…it's part of my .files repo as well.…So it's eslintrc.js in here.…And this configuration uses the Babel ESLint…and the main recommended ESLint rules…plus the recommended React plugin rules…and a few customizations.…

So we'll add this file under TargetSum…as .eslintrc.js.…And to get this file to work,…we need to install a few dependencies.…So npm install, these are development dependencies, so -D.…We need eslint itself.…I also need babel-eslint because my configuration…uses that as a parser.…And I need eslint-plugin-react.…So you need all three of these packages…if you're using my exact same customized configuration.…