Render and deploy program guidelines as a website

I expect the content to grow quickly as soon as we start #5. Putting everything in a huge `README.md` is quickly getting confusing and loosing structure. Navigating between different markdown files directly on GitHub is far from being ideal in my opinion. Especially the missing navigation makes it difficult to get the context if following a link to a subdocument.

I propose that we use [guidemaker](https://github.com/empress/guidemaker) instead to render the program guidelines as an interactive website.

It could be hosted on Netlify. GitHub Pages are not supported by Guidemaker right now due to https://github.com/empress/guidemaker/issues/19.