Examine source code of Permanent Inspect Element

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Permanent Inspect Element",
  "version": "0.1.1",
  "description": "Save the changes you make to a page with Inspect Element so they wouldn't go away after refreshing",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "jquery-3.3.1.js",
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{894284df-aca5-4603-b3b0-43c179c1cf85}"
    }
  }
}