You can use a template repository on GitHub as starter code for an assignment on GitHub Classroom. Your template repository can contain boilerplate code, documentation, and other resources for your students. For more information, see Creating a template repository.
To use the template repository for your assignment, the template repository must be owned by your organization, or the visibility of the template repository must be public.
When you create your assignment, GitHub Classroom creates a new repository from the template in your organization with the visibility you select (for more information on creating repositories from templates, see Creating a repository from a template).
Student assignment repositories will be forks of this created repository. You can choose whether all branches are included in student assignment repositories, or just the default branch.
You can reuse an existing assignment, even if it uses a template repository, in any other classroom that you have admin access to, including classrooms in a different organization. For more information, see Reuse an assignment.