Show Author Name for each post

[debuggingfuture]

We should add in workflow to identify who is the author, since sometimes we have "guest blogger".
Possible to capture directly from the pull request?(i.e. github id)
In case of official post, we can have it as this org (i.e. code4hk)

[debuggingfuture]

this should also be in RSS

[hupili]

We thought alike! I didn't see the issue until commit ee20f45

People just add themselves in the front matter:

http://blog.code4.hk/hackathon/2014/02/23/blog-is-up/

This allows more customization, e.g. define his/her own link, instead of a GitHub handle.