making small fix to examples.json
making small fix to examples.json

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