Adding canonical meta tag as suggested in https://github.com/revel/revel/issues/699, this is supposed to instruct search botson which is the preferred URL for documentation pages (https://support.google.com/webmasters/answer/139066?rd=1).
Fixing "canonical" typo in comment.
Merge pull request #4 from xiam/gh-pages

Adding "canonical" meta tag for search bots