Update to the install readme
Update to the install readme

Original PR: https://github.com/cucumber/cucumber.github.com/pull/43

Found that development environment is needed, and that cucumber --help produces the different options for cucumber.

cucumber/website,nhashmi/website,chiranjith/website,dandv/website,maxmeyer/cucumber-website,chiranjith/website,davidjlowe/website,dg-ratiodata/website,bit-whacker/website,bit-whacker/website,nhashmi/website,chiranjith/website,chiranjith/website,nhashmi/website,cucumber/website,cucumber/website,maxmeyer/cucumber-website,maxmeyer/cucumber-website,bit-whacker/website,davidjlowe/website,dg-ratiodata/website,dandv/website,davidjlowe/website,dandv/website,dg-ratiodata/website