Examine source code of Delay Distraction

{
  "manifest_version": 2,
  "name": "DelayDistraction",
  "version": "1.0",
  "description": "Delay loading pages so you can focus",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/content_script.js"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_action": {
    "default_icon": "icons/browser_action_icon.png",
    "default_title": "DelayDistraction",
    "default_popup": "src/browser_action/browser_action.html"
  }
}