Examine source code of NewsGuard

{
  "manifest_version": 2,
  "name": "NewsGuard",
  "description": "NewsGuard's rating shields and labels help users know which news and information websites to trust.",
  "version": "5.10.2",
  "short_name": "NewsGuard",
  "icons": {
    "16": "/assets/icons/png/NewsGuard_Shield_16.png",
    "48": "/assets/icons/png/NewsGuard_Shield_48.png",
    "128": "/assets/icons/png/NewsGuard_Shield_128.png"
  },
  "author": "support@newsguardtech.com",
  "permissions": [
    "tabs",
    "storage",
    "nativeMessaging",
    "https://*/*",
    "http://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "NewsGuard",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "firefox@newsguardtech.com"
    }
  }
}