Add "getting started" section

[ffont]

Our current website lacks the "getting started" section which will be the place to go for potential audio commons users, service developers and tool developers to know how to use Audio Commons. We should make it as visually appealing as possible and include links to tools, tutorials, documentation, etc.

[ffont]

See my attempt with the new website design here: www.audiocommons.org/new-website-demo/
I added the "tools" section which should contain entries for the getting started. I added a couple of fake posts but real content should be added. This can include api clients, docs on how to use api, ac extractor, ontology, etc...