Examine source code of RandomNick

{
  "manifest_version": 2,
  "name": "RandomNick",
  "version": "1.0",
  "description": "Generate random nicknames for signing up to websites",
  "icons": {
    "48": "icons/randomNick-48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "random-nick": {
      "suggested_key": {
        "default": "Ctrl+Alt+Up",
        "linux": "Ctrl+Alt+Up"
      },
      "description": "Generate random nicknames for signing up to websites"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "randomNick.js"
      ]
    }
  ],
  "permissions": [
    "contextMenus",
    "tabs",
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1272aeec-9bfc-4614-af27-42e1b33b4877}"
    }
  }
}