List starred gists

Hi,

as API says, It's possible and would be very handy :).
https://developer.github.com/v3/gists/#list-starred-gists

Start with the GitHub API documentation linked in the issue, specifically the “List starred gists” endpoint, then inspect the repository’s existing gist-related entry points to find where API wrappers are defined. Done means exposing this endpoint through the JavaScript wrapper and covering the behavior with the repository’s existing tests, if present.

由索引模型根据 Issue 内容生成。