Add data files to supplementary package

[arlin]

Currently this is blocked by #41 IRB approval. Once the approval is done, we can move all of the data files (except demographics)from the private repo into the public hip_hack_howto repo. We do not need the stuff in nead_data on the private repo. All the key data files are at the top level.

You will need to

• decide on a directory structure
• move over the files
• make sure the README is good