Examine source code of Website Timer Blocker

{
  "manifest_version": 2,
  "name": "Website Timer Blocker",
  "version": "1.0",
  "description": "Tracks time spent on specific websites and blocks them after a set limit.",
  "permissions": [
    "tabs",
    "storage",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3c7d0619-dec9-411b-8aeb-c72b3e65a976}"
    }
  }
}