Fixed capitalization
Fixed capitalization

Fixed capitalization of ES6 to match the rest of the README.
xalexec/javascript,LodoSoftware/javascript-style-guide,codelegant/JavaScript,getjll/JavaScript-Style-Guide,naustudio/javascript,practicefusion/javascript,appcom-interactive/javascript,pokelondon/javascript,cloudability/javascript-style-guide,addshoppers/javascript,naustudio/javascript,nulogy/javascript,codelegant/JavaScript,LodoSoftware/javascript-style-guide,whichdigital/javascript-coding-standards,webcoding/javascript-style-guide,airbnb/javascript,ljharb/javascript,allanfish/javascript,bl00mber/javascript