Examine source code of Jisho Mahou

{
  "manifest_version": 3,
  "name": "Jisho Mahou",
  "version": "1.1",
  "description": "Improve the jisho.org experience",
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "https://jisho.org/*"
      ]
    }
  ],
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "gieraltowski.har@gmail.com"
    }
  }
}