Examine source code of GitHub Dracula Theme

{
  "manifest_version": 2,
  "name": "GitHub Dracula Theme",
  "short_name": "GitHub Dracula Theme",
  "description": "A Dark theme for all of GitHub based on Dracula. Forked from https://github.com/poychang/github-dark-theme",
  "version": "1.1.0",
  "applications": {
    "gecko": {
      "id": "{73972DAE-4E11-11EA-88B3-062DFC2CA371}"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.github.com/*"
      ],
      "run_at": "document_start",
      "css": [
        "app/app.css"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}