Readme link to new project is broken

[citadelgrad]

This link is broken in the Readme. If I could find the correct link, I'd have provided a pull request.

For v6 onwards please follow the new projects guide.

[mikehardy]

Yeah there's no real starter project anymore but I do maintain a demonstrator that I (mostly) use to prove things work from a clean state for people with issues https://github.com/mikehardy/rnfbdemo/blob/master/make-demo-v6.sh