Examine source code of BetterPixiv

{
  "manifest_version": 3,
  "name": "BetterPixiv",
  "version": "1.0.3",
  "description": "Pixivを閲覧しやすくする拡張機能です。",
  "icons": {
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "betterpixiv@example.com",
      "strict_min_version": "128.0"
    },
    "gecko_android": {
      "strict_min_version": "128.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.pixiv.net/*"
      ],
      "js": [
        "libs/jszip.js",
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": false,
      "world": "MAIN"
    }
  ]
}