Adds a way to add custom link tags.

This is for adding style-sheets when we use the gem as a jekyll template. I had tried to make syntax highlighting work with rouge. But the style-sheets would just get messed up or not work. I put them under (root_dir)/assets/css/base16.highlight.css

Allow users to disable ga tracking

Sometimes people would not want GA-tracking. So they can turn it off. By default its enabled. For backward compatibility

Adds proper meta tags for opengraph

This helps when people give a link to your website and they get a proper link preview with title description and image.

Thanks.