Examine source code of Security Headers Checker

{
  "manifest_version": 2,
  "name": "Security Headers Checker",
  "version": "1.1",
  "description": "A Mozilla extension to check website security headers and provide recommendations.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "storage",
    "notifications",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/logo_64.png"
  },
  "icons": {
    "64": "icons/logo_64.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d371b7fd-77b5-437a-9bde-72d67fa81cad}"
    }
  }
}