Added the codeblock lang to highlightjs, rather than pure autodetection
Added a code alias of `coffee` for `coffeescript`
Removed the marked language prefix of `lang-`

The purpose for this was that highlight.js' default styling only styled
for `markdown` instead of `lang-markdown`. This may not be the best
workaround, but i don't believe there are any downsides currently.
Specified markdown for the codeblocks
Merge branch 'master' of github.com:koding/kdlearn