Add magic icon for Stack Exchange SOCIAL thing

[tshepang]

I added my Stack Exchange profile to SOCIAL collection, and I get this:

You can access this from any of my posts.

[talha131]

Replace stack exchange with stack-exchange

('stack-exchange', 'http://stackexchange.com/users/125744/tshepang')

You can also add RSS icon

('rss', 'http://tshepang.net/feeds/all.atom.xml')

[tshepang]

Why one works and the other does not?

[talha131]

Elegant uses Font Awesome icons for Social links. Each social site name should be picked from there minus the fa- part.

So fa-linkedin will become linkedin and so on.

[tshepang]

Oh, I see. This needs a lil' bit of documenting. I was so lost, searching pelican-themes and pelican repos, without success.

[talha131]

Yeah, it will get its documentation when V1.4 gets released. See #53