Improve “Get Started” section of README.
Improve “Get Started” section of README.

It’s important that you see the expectation fail
(it’s how you “test the test”, so to speak, and
you can confirm it gives you a good failure message),
so let’s not skip that step.
leg100/rspec-core,SoldierCoder/rspec-core,a-suenami/rspec-core,leg100/rspec-core,pandabrand/rspec-core,behnaaz/rspec-core,a-suenami/rspec-core,SoldierCoder/rspec-core,avantcredit/rspec-core,urbanautomaton/rspec-core,h4ck3rm1k3/rspec-core,eugeneius/rspec-core,edwardpark/rspec-core,yaoshipu/rspec-core,yaoshipu/rspec-core,dg-ratiodata/rspec-core,irfanah/rspec-core,behnaaz/rspec-core,xmik/rspec-core,h4ck3rm1k3/rspec-core,pandabrand/rspec-core,azbshiri/rspec-core,danascheider/rspec-core,danascheider/rspec-core,eugeneius/rspec-core,maclover7/rspec-core,maclover7/rspec-core,irfanah/rspec-core,h4ck3rm1k3/rspec-core,Teino1978-Corp/Teino1978-Corp-rspec-core,SoldierCoder/rspec-core,xmik/rspec-core,danascheider/rspec-core,azbshiri/rspec-core,azbshiri/rspec-core,irfanah/rspec-core,Teino1978-Corp/Teino1978-Corp-rspec-core,rspec/rspec-core,rspec/rspec-core,dg-ratiodata/rspec-core,maclover7/rspec-core,xmik/rspec-core,urbanautomaton/rspec-core,a-suenami/rspec-core,iguchi1124/rspec-core,rspec/rspec-core,dg-ratiodata/rspec-core,arronmabrey/rspec-core,avantcredit/rspec-core,yaoshipu/rspec-core,arronmabrey/rspec-core,arronmabrey/rspec-core,urbanautomaton/rspec-core,pandabrand/rspec-core,edwardpark/rspec-core,leg100/rspec-core,eugeneius/rspec-core,iguchi1124/rspec-core,Teino1978-Corp/Teino1978-Corp-rspec-core,iguchi1124/rspec-core,avantcredit/rspec-core,behnaaz/rspec-core,edwardpark/rspec-core