Examine source code of GitHub Icons

{
  "manifest_version": 2,
  "name": "GitHub Icons",
  "description": "Replace GitHub file and folder icons with distinct, colorful glyphs.",
  "version": "0.8.0",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png"
  },
  "permissions": [
    "storage",
    "https://github.com/*"
  ],
  "web_accessible_resources": [
    "icons/*",
    "manifests/*"
  ],
  "browser_action": {
    "default_title": "GitHub Material Icons",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0f35aabc-8d8b-4380-9dc5-c2a70ccb0459}"
    }
  }
}