Examine source code of Jokes Extension

{
  "name": "Jokes Extension",
  "version": "0.0.1",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "logo.png"
  },
  "icons": {
    "128": "logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6a93de30-b0fa-475e-b6c1-a94a04d888f6}"
    }
  }
}