Examine source code of Typeform Contentful links

{
  "manifest_version": 2,
  "name": "Typeform Contentful links",
  "description": "Adds links to Typeform.com to take you directly to an entry on Contentful.com",
  "version": "2.0.0",
  "content_scripts": [
    {
      "matches": [
        "https://www.typeform.com/*",
        "https://app.contentful.com/*",
        "https://*.herokuapp.com/*",
        "http://localhost/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "permissions": [],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "typeform-contentful-links@typeform.com"
    }
  }
}