Examine source code of Material Icon for GitHub

{
  "manifest_version": 2,
  "name": "Material Icon for GitHub",
  "author": "Nanashi. (@sevenc-nanashi)",
  "version": "1.0",
  "description": "Adds material icon to GitHub.",
  "icons": {
    "24": "./icons/folder-github.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://github.com/*"
      ],
      "js": [
        "icon.js"
      ]
    }
  ],
  "permissions": [
    "*://*.github.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9be2e5ea-fd9b-40d9-b5cb-ad5f5e0f2c96}"
    }
  }
}