Make Repository a Template Repository

[chaitunya]

I feel that this repository would work well as a template repository, since this serves as a template for Mailspring themes.

From the link:

Creating a repository from a template is similar to forking a repository, but there are important differences:

• A new fork includes the entire commit history of the parent repository, while a repository created from a template starts with a single commit.
• Commits to a fork don't appear in your contributions graph, while commits to a repository created from a template do appear in your contribution graph.
• A fork can be a temporary way to contribute code to an existing project, while creating a repository from a template starts a new project quickly.

[Icelk]

Seems like a great addition!

[bengotow]

Oh hey this seems like a great idea! I didn't even know these existed actually :-) I checked the box and it seems like that's all there is to it, will do it on the plugin starter as well!