There are dozens of static site generators, all of them try to do too much for my taste.

the first two lines are all you need to change, define the name of a template file and the name of your content files. The content files will need a leading underscore, and once compiled this will be removed, so if you want the resulting file to be foo.html, your content file needs to be _foo.html

Running build.rb will check the current dir and all subdirs for content files and will build a live file with the template for each one it finds.

The template file will need to contain: {content} where the content should go.