[Github] separate rule for github pages

Some github pages are not designed for https due to mixed content, and aren't motivated to fix
because their primarily purpose is to CNAME a vanity domain (which can't support SSL).
This makes it easier to work with those pages - especially for dev & testing - without disabling
all of Github
Merge branch 'githubpages' of https://github.com/yardenac/https-everywhere into yardenac-githubpages
Merge branch 'yardenac-githubpages'