Here's (another) reference for a "Edit on GitHub" button, at the top under the title: http://a11yproject.com/posts/how-to-hide-content/

@arthurvr @agcolom is this something you could look into? Maybe put it on the content meeting agenda, for a start.

Here's another reference: http://givan.se/ember-i-choose-you - the "errata" link gets a question mark cursor, has a "Found typos or inaccuracies?" title and links to the source file on GitHub.