* Update dependencies

* Use published version of eslint-config-react-app for development

We dogfood on our eslint-config-react-app by using it as our ESLint config,
but installing it from the local folder causes problems when its peerDependencies
are updated, because npm won't update it unless the version number changes.

Use the published version for dogfooding so it can be installed from npm.

* Move ESLint configuration to a separate package

* Remove the ESLint configuration, moved to eslint-config-react-app

* Update ESLint instructions

* Pin the package versions in eslint-config-react-app

* Add a README for eslint-config-react-app

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update package.json

* Update package.json

* Update production eslint-loader config

* Add the ESLint config to devDependencies of the repo