How to share a D8 configuration without the UUID limitation? How can I share a Drupal 8 configuration (content type, custom view/menu/block, etc.) with another website without the UUID limitation?

Each site has a unique UUID, and refuses to work with the configuration file of another website. It's a big problem that doesn't allow users to share their configuration with the world.
The best way is to use the features module which is pretty stable and useful. You can even bundle specific configs and install them later on any website as a module (thus not needing to install the module there).