Examine source code of AWS Favicon Update

{
  "manifest_version": 2,
  "name": "AWS Favicon Update",
  "description": "IAM shouldn't be the only tab with a unique favicon!  This sets favicons for many AWS services, so your tabs make more sense.",
  "version": "1.9",
  "author": "Jaime Barriga",
  "icons": {
    "16": "colorcube16.png",
    "48": "colorcube48.png",
    "128": "colorcube128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.aws.amazon.com/*",
        "https://*.amazonaws-us-gov.com/*"
      ],
      "js": [
        "faviconupdatefirefox.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "icons/*"
  ]
}