Examine source code of Touch Grass

{
  "manifest_version": 3,
  "name": "Touch Grass",
  "version": "1.2.0",
  "description": "Turns GitHub contribution graphs into animated grass fields",
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "https://github.com/*"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "touch-grass@lukeocodes",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}