Examine source code of comicweb

{
  "manifest_version": 2,
  "name": "comicweb",
  "version": "1.0.1",
  "description": "An extension to ruin typography. Changes all fonts to Comic Sans MS (if installed).",
  "icons": {
    "48": "comicweb.png"
  },
  "permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "comicweb.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{be5a3990-559b-49ac-bd1f-bf71118d6a36}"
    }
  }
}