* 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
