Is there a service that can replace RawGit for Gists, specifically serving them with the correct MIME type? This was a convenient feature for users of https://

Is there a service that can replace RawGit for Gists, specifically serving them with the correct MIME type? This was a convenient feature for users of https://reviewable.io https://reviewable.io to hack up a quick custom stylesheet or keyboard shortcuts override. It's not clear to me whether any of the suggested replacements support Gists.