Refine Development section in README

[dcwalk]

Takes over the last section of the README, from #3.

Currently reads

## Installation 

Use in any golang package with:

`import "github.com/datatogether/cdxj"`

## Development

Coming Soon

[dcwalk]

Blurb for technical documentation: Technical documentation can be built with godoc . or, if your $GOPATH and repo structure is set up correctly, with something like godoc -http=:6060 & followed by browsing to http://localhost:6060/pkg/github.com/datatogether.

Technical documentation can be built with godoc . or, if your $GOPATH and repo structure is set up correctly, with something like godoc -http=:6060 & followed by browsing to http://localhost:6060/pkg/github.com/datatogether.