Link to the github file from each page of the website for easier collaboration

[PerWiklander]

I'm lazy, but I've heard that's a good trait for a developer :-)

I was reading the docs of the new homepage and wanted to submit a pull request to correct some minor errors on a specific page. It would have been much easier if the page had an "Improve this doc" link right there on the page (like in the footer).

The Jekyll help (https://github.com/jekyll/jekyll-help/issues/5) says:

If you're hosting the site on GitHub Pages, they inject the source repository into a variable called site.github.repository_url which you can use in combination with page.path to wire up the URL on github.com.

Example: <a href="{{site.github.repository_url}}/blob/gh-pages/{{page.path}}">Improve this doc</a>