This feature allows you to save a post's content and use it as a starting point for new posts.
If post layouts are enabled, a "save layout" button will appear at the top of the page when editing a post. Click this button to create a template using the current post content.
After saving your first layout, another button labelled "load layout" will appear right next to the first one. Click this button for a list of all available post layouts that you can load as a starting point for new posts. Using this button, you can also rename or delete existing post layouts.