Squashed 'GithubCard/' content from commit 3a91e41

git-subtree-dir: GithubCard
git-subtree-split: 3a91e4177504c665e0f638e1d02ef00e32215538
Merge commit '64d619ffb3000b09539b4f90bc1f687873160378' as 'GithubCard'
Merge pull request #3 from chekun/master

增加Github Card for Typecho插件