Examine source code of Smart Decoder

{
  "manifest_version": 2,
  "name": "Smart Decoder",
  "version": "1.0",
  "description": "Automatically detect and decode highlighted text",
  "permissions": [
    "contextMenus",
    "activeTab",
    "clipboardWrite"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{25bb3169-91b8-4454-894c-7c6f3980f0bf}"
    }
  }
}