Examine source code of GitHub File Diff

{
  "manifest_version": 3,
  "name": "GitHub File Diff",
  "version": "1.2.3",
  "description": "View diffs of files and directories on GitHub.",
  "icons": {
    "16": "icon.png",
    "48": "icon.png",
    "128": "icon.png",
    "256": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6b9721da-5fa4-4e58-a67b-5eb9294665e2}"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*"
      ],
      "css": [
        "vendor.css"
      ],
      "js": [
        "vendor.js",
        "main.js"
      ]
    }
  ]
}