What is Caddyfile file type?

I'm using PhpStorm to develop a project.

I have created a Caddyfile to configure my caddy server.

But PhpStorm doesn't format or highlight the code of the Caddyfile.

I know that I can change the File Type for specific file but I don't know which File Type I should choose for Caddyfile.

What is Caddyfile File type in intellij idea?