Examine source code of Distraction Blocker

{
  "manifest_version": 2,
  "name": "Distraction Blocker",
  "version": "1.0",
  "description": "Block distracting websites during working hours (9 AM - 5 PM).",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{78179098-d956-490b-91c8-8694ffb7b755}"
    }
  }
}