Examine source code of Page Title Changer

{
  "manifest_version": 3,
  "name": "Page Title Changer",
  "description": "Quickly changes the page title to whatever text you've highlighted.",
  "version": "1.0",
  "permissions": [
    "scripting",
    "contextMenus",
    "activeTab",
    "storage"
  ],
  "icons": {
    "128": "icon128.png"
  },
  "background": {
    "scripts": [
      "service_worker.js"
    ],
    "type": "module"
  },
  "commands": {
    "1changeTitle": {
      "suggested_key": {
        "default": "Alt+X"
      },
      "description": "Change Page Title"
    },
    "2appendTitle": {
      "suggested_key": {
        "default": "Alt+C"
      },
      "description": "Append to Page Title"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "action": {
    "default_title": "Extension Options",
    "default_popup": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{754f2e70-581d-44b3-b3f3-f091c3828342}"
    }
  }
}