The website simplytest.me creates a temporary sandbox site with a chosen project enabled. In a demo, you might want some sample content, need an API key to be set, or another module to be enabled. This page will describe different methods to provide example content for your demo on simplytest.me.
Ref:
- https://www.drupal.org/docs/develop/documenting-your-project/using-simplytestme-as-a-project-demo
- https://www.drupal.org/project/simplytest
I contributed to simplytest by porting the module named simplytest_import from there drupal 7 codebase to Drupal 8.
Ref:
All bugs, feature requests, pull requests, feedback, etc., are welcome. Create an issue.