Examine source code of MetNews

{
  "name": "MetNews",
  "description": "Your bookmark manager, with full text search and feed auto discovery.",
  "version": "1.0.1",
  "manifest_version": 2,
  "homepage_url": "https://metnews.co",
  "icons": {
    "512": "./icons/icon.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "http://127.0.0.1/*",
    "http://localhost/*",
    "https://*.metnews.co/*"
  ],
  "background": {
    "scripts": [
      "./dist/background_script.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_title": "MetNews",
    "default_icon": {
      "512": "./icons/icon.png"
    }
  },
  "content_scripts": [
    {
      "all_frames": false,
      "js": [
        "./dist/content_script.js"
      ],
      "css": [],
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    "icons_active/*.png",
    "icons_normal/*.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c2f225f0-9d80-452d-801b-55fdf9c01a07}"
    }
  }
}