Added Capro - static site generator

README.md

 ### Static Site Generators
 *Tools for pre-processing content to generate web pages.*
 
+* [Capro](https://capro.xy2z.io) - Flexible static site generator with Blade templates and Markdown support.
 * [Couscous](http://couscous.io) - Couscous turns Markdown documentation into beautiful websites. It's GitHub Pages on steroids.
 * [Jigsaw](https://jigsaw.tighten.com/) - Simple static sites with Laravel's Blade.
 * [Sculpin](https://sculpin.io) - A tool that converts Markdown and Twig into static HTML.