Use HTML comments to template the markdown

[avivace]

To not keep duplicates of the resource list and keep the website (gbdev.io) and this list in sync (https://github.com/gbdev/gbdev.github.io/issues/8), we could think about using a templating system putting variables in HTML comments, so this markdown (render) doesn't change but the same file can be used by a pipeline in https://github.com/gbdev/gbdev.github.io/ to generate the webpages