corrected a  comment
corrected a  comment

evolighting/webextensions-examples,anaran/webextensions-examples,evolighting/webextensions-examples,matthewjwein/webextensions-examples,matthewjwein/webextensions-examples,matthewjwein/webextensions-examples,anaran/webextensions-examples,mdn/webextensions-examples,evolighting/webextensions-examples,mdn/webextensions-examples,mdn/webextensions-examples,andymckay/webextensions-examples,andymckay/webextensions-examples