Examine source code of Keyword Alerter

{
  "manifest_version": 2,
  "name": "Keyword Alerter",
  "version": "1.4",
  "description": "Scans web pages for specific keywords and sends a notification.",
  "permissions": [
    "storage",
    "notifications",
    "tabs",
    "<all_urls>",
    "alarms"
  ],
  "web_accessible_resources": [
    "icons/icon-48.png"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "keyword-alerter@lentro"
    }
  }
}