In order to create a Google sitemap follow these steps.
Navigate to the project settings and select "Generate Search Engine Sitemap".
You are able to register the sitemap inside Google Webmaster Tools: https://search.google.com/search-console
There, you have to:
- Create an Google Account (or use an existing one)
- Add your website (with the help of a google verification code, where you have to add a html file into your project, or add a meta tag ti your index page)
- Add the link to your sitemap.xml (the default one generated by RapidWeaver)