Examine source code of Content Editable

{
  "manifest_version": 3,
  "name": "Content Editable",
  "version": "0.3.0",
  "description": "Effortlessly toggle 'contenteditable' attribute on the body tag for manual layout testing. Streamline your evaluation of text overflow with a single click.",
  "homepage_url": "https://github.com/nadProg/content-editable-extension",
  "author": "Eugene Skrobov <skrobov.ev@gmail.com>",
  "icons": {
    "16": "assets/icon.png",
    "24": "assets/icon.png",
    "32": "assets/icon.png",
    "48": "assets/icon.png",
    "128": "assets/icon.png"
  },
  "action": {
    "default_icon": {
      "16": "assets/icon.png",
      "24": "assets/icon.png",
      "32": "assets/icon.png",
      "48": "assets/icon.png",
      "128": "assets/icon.png"
    },
    "default_title": "Content Editable",
    "default_popup": "popup.html"
  },
  "background": {
    "page": "background.html"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "skrobov.ev@gmail.com",
      "strict_min_version": "109.0"
    }
  }
}