Examine source code of Text Processing Extension

{
  "manifest_version": 2,
  "name": "Text Processing Extension",
  "version": "1.0.5",
  "description": "magic text field",
  "author": "Holthuizen",
  "permissions": [
    "storage",
    "notifications",
    "clipboardWrite"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Magic Text Field",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "TPE@holthuizen",
      "strict_min_version": "119.0"
    }
  }
}