Loads reusable Markdown prompt content. Unqualified names resolve project, user, installation, then the deprecated project-skill location. A vloop: reference resolves package content first, then project content.
File name without .md, or a vloop:/ reference.
Optional
Loads reusable Markdown prompt content. Unqualified names resolve project, user, installation, then the deprecated project-skill location. A vloop: reference resolves package content first, then project content.