Update Publishing Datasets docs for 2.0

http://docs.ckan.org/en/latest/publishing-datasets.html

Embedding a google docs presentation into the docs seems bad, won't this break things like linking/referencing between docs pages, search engine hits, the printed/pdf version of the docs, etc.? Also the presentation is only four slides long and is all text what's the point! Just put it in the docs

The point of this chapter in the docs seems to be to explain some of CKAN's key concepts: dataset, resource, metadata, linking to files hosted elsewhere files vs uploading them to the filestore ... This seems like a good idea but it needs bringing up to date with CKAN's current feature set (some key features seem to be missing) and it should probably be moved nearer the beginning of the docs.

- [ ] Change the google docs presentation into normal documentation text
- [ ] Update the text to reflect CKAN 2.0's feature set
- [ ] Add links, e.g. it mentions that you can upload files to CKAN, this should link ot the filestore page of the docs
- [ ] Move it to a better place in the docs
- [ ] Remove the links to old blog posts about CKAN 1.x (We should probably document things in the docs not by linking to blog posts, as with the google presentation it'll break stuff like the pdf version)