Examine source code of News Date

{
  "description": "__MSG_extDescription__",
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "version": "0.0.2",
  "homepage_url": "https://github.com/ettoolong/NewsDate",
  "browser_specific_settings": {
    "gecko": {
      "id": "NewsDate@ettoolong",
      "strict_min_version": "66.0"
    }
  },
  "developer": {
    "name": "Ett Chung",
    "url": "https://github.com/ettoolong/NewsDate"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file:///*"
      ],
      "js": [
        "js/moment.min.js",
        "js/content-script.js"
      ],
      "css": [
        "css/tag.css"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "permissions": [
    "storage"
  ],
  "default_locale": "en",
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false,
    "browser_style": true
  }
}