Examine source code of UUID-Generator

{
  "manifest_version": 2,
  "name": "UUID-Generator",
  "version": "1.0",
  "description": "Generate and write to the clipboard a random/empty universally unique identifier (UUID).",
  "icons": {
    "48": "icons/play_icon.png"
  },
  "permissions": [
    "contextMenus",
    "clipboardWrite",
    "clipboardRead"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contentscript.js"
      ]
    }
  ]
}