Publications

Publication creation and document addition.
- Admin can now add publications and documents to those publications. 
- Documents can be added either by uploading them or by referencing them with a url.
This and line 9 above is something we're doing a lot but there really a security red flag. Maybe it's fine to leave it for now because we need to address these across the whole app and maybe others and I'm not sure how best to address them but let's keep an eye out for using `params` like this and try to avoid it in the future.