Add README pointing to go bindings repo

Instead of adding the code for the go bindings to this repository it is favourable to put them in their own dedicated repo. This is more compatible with golang's dependency resolution mechanism.

They can now be installed with a simple `go get github.com/mkilling/goejdb`

I think that adding a README pointing to where the go bindings can be found is a good way to keep an overview of all available bindings in the main repo.