Examine source code of Blokhead

{
  "manifest_version": 2,
  "name": "Blokhead",
  "description": "Block websites. Stay focused.",
  "version": "1.0.0",
  "icons": {
    "16": "assets/icons/icon-16.png",
    "32": "assets/icons/icon-32.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "permissions": [
    "storage",
    "declarativeNetRequest",
    "declarativeNetRequestWithHostAccess",
    "alarms",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "web_accessible_resources": [
    "blocked.html",
    "assets/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Blokhead",
    "default_popup": "popup.html"
  },
  "sidebar_action": {
    "default_panel": "sidepanel.html",
    "default_title": "Blokhead Settings"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "blokhead@blokhead.app",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}