Install instructions seem inaccurate

[gerry-c-wd]

In readme, the directions for a local install are as follows:

jenkins-x-platform/README.md

Lines 32 to 41 in 364e54c

	## Local development
	For local development we can install Jenkins X with minikube.
	First install the Hyperkit driver https://github.com/kubernetes/minikube/blob/master/docs/drivers.md#hyperkit-driver
	```
	git clone https://github.com/jenkins-x/cloud-environments && cd cloud-environments
	jx create cluster minikube --local-cloud-environment=true
	```

However that flag doesn't seem to work any more.

> jx create cluster minikube --local-cloud-environment=true
Error: unknown flag: --local-cloud-environment


Available Commands:
  create project alias for: jx project
  create pullrequest alias for: jx pullrequest
  create quickstart alias for: jx quickstart
  create spring alias for: jx spring

I can see there hasn't been updates to this project for 15 months, so perhaps there is no longer interest? If so, would it be possible to put a warning at the top of the readme?