Add link to all contributors

As well @Walkman100? Hmm, but @arvida change this.

Look at this: [https://github.com/arvida/emoji-cheat-sheet.com/commit/0533bc7fd1c2047ade9c23812319894d2d8a4921](https://github.com/arvida/emoji-cheat-sheet.com/commit/0533bc7fd1c2047ade9c23812319894d2d8a4921)