Examine source code of Reddit Detox

{
  "manifest_version": 2,
  "name": "Reddit Detox",
  "version": "1.0",
  "description": "Block Reddit during designated hours",
  "icons": {
    "16": "icons/icon16.jpg",
    "48": "icons/icon48.jpg"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "https://www.reddit.com/*",
    "https://old.reddit.com/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.jpg",
      "48": "icons/icon48.jpg"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.reddit.com/*",
        "*://old.reddit.com/*"
      ],
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{69ef251a-680b-4bf7-839f-7ce8e5596b12}"
    }
  }
}