How do filenames work in Hammer?
In a Hammer project, you create all your templates in your project folder. Inside, Hammer creates a Build directory, and processes all of your files into it. That means, when you're ready, you can publish just the Build directory to your server.
Underscores
If a Hammer file starts with an underscore, it's treated as an included file. That means it isn't compiled directly into the Build directory, but can be included inside other files.
That's why you should use filenames like _header.html for included files. Otherwise, if you try to use a variable in header.html without defining it in the same file, header.html will fail to build.
The same goes for SASS & SCSS files - _style.scss won't be compiled into Build/_style.css.
