chore(docs): grunt-ngdocs setup

Adds ngdocs task.

Run `npm install` and then `grunt ngdocs`.  

It will create the docs in `dist/docs/` (dist/docs/ is on gitignore)

Run some sort of http server and open dist/docs to try it out.

Notes;
- I moved the 'doc' folder to 'doc-old' - we can move stuff out of it then get rid of it.
- I added a 'docs' folder which contains some content for docs, and the template for our docs navbar.

TODO: 
- Make automated grunt task or shell script to deploy docs to gh-pages