Improve Webstorm doc: fix numeration, add info about ES7 support, add details about ESLint package selection and some minor formatting fixes
Improve Webstorm doc: fix numeration, add info about ES7 support, add details about ESLint package selection and some minor formatting fixes

standard/standard,SimenB/standard,LinusU/standard,SimenB/standard,feross/standard,standard/standard,feross/standard,jasonpincin/standard,JedWatson/happiness,JedWatson/happiness,LinusU/standard