* Add GitHub link to header

* Add GitHub link to footer

* Add link to Stack Overflow

* Add Twitter link

* Add the repoUrl prop to the siteConfig

* Switch out Discord with Spectrum

* Add a temporary README file

This commit adds a temporary readme file that points users to the
main README file or the User Guide.

* Add a "getting started" doc

This commit adds a page for getting started, copying the
"Get started now" from the current `README.md`.

* Add link to the get started page from the index page

* Add the getting started doc to the site header

* Add footer link to getting started info

* Add getting started to the sidebar

* Add placeholder for the user guide page

* Add links to the user-guide page as well

* Add auto-generated i18n file

* Move all docusaurus related files into own folder

 - 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

create-react-app-parcel is failing and there is no support for that.

* Caches the Yarn resolution for faster installs

* Adds the yarn.lock.cached file to the publish list

* Removes the copied lockfile when the install fails

* Updates the release checklist

* 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