* Always type check TypeScript when being used

* Use alternate version

explictly seems like a typo for explicitly

 - babel-preset-react-app@5.0.4
 - confusing-browser-globals@1.0.4
 - create-react-app@2.0.4
 - eslint-config-react-app@3.0.4
 - react-dev-utils@6.0.5
 - react-error-overlay@5.0.5
 - react-scripts@2.0.5

* Added note on update to .flowconfig for .scss imports

Added a note aimed at Flow users on how to get Flow to recognize the .scss imports.

* Mentioned .sass extension in note, added backticks

Current instructions for running using HTTPS in a PowerShell prompt are incorrect and do not work on Windows 10 v1809

* Add environment variable to optionaly disable inlining of chunks

* Changed env var to `process.env.INLINE_RUNTIME_CHUNK `

* Added env var to Advanced Configuration in docs

* Drop implied behavior

* Tweak working to match other descriptions

* Fix broken link in main README

* Fix incorrect link in user guide README

It seems correct URL is https://developers.google.com/web/fundamentals/web-app-manifest/
Current URL (https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/) is redirecting to there.

* avoid TypeError on when registering service workers without config

Fixes #5299

* same before config.onUpdate

* add react-testing-library documentation/examples

* make react-testing-library a heading

* fix typo

 - babel-preset-react-app@5.0.3
 - create-react-app@2.0.3
 - react-dev-utils@6.0.4
 - react-error-overlay@5.0.4
 - react-scripts@2.0.4

* Add `.mjs` support back to webpack, because webpack was not the problem

* Continue toggling `.mjs` to `javascript/auto` mode

* Be more inline with the specification

* Bump old Node to 6

 - babel-plugin-named-asset-import@0.2.2
 - babel-preset-react-app@5.0.2
 - confusing-browser-globals@1.0.3
 - create-react-app@2.0.2
 - eslint-config-react-app@3.0.3
 - react-app-polyfill@0.1.3
 - react-dev-utils@6.0.3
 - react-error-overlay@5.0.3
 - react-scripts@2.0.3

* Adds instructions to create a Bootstrap theme with Sass

* Update README.md

* Update README.md

* Update README.md