Examine source code of LaTeX for Messenger

{
  "manifest_version": 3,
  "name": "LaTeX for Messenger",
  "version": "4",
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "description": "Render mathematical notation in Messenger on the Facebook website.",
  "content_scripts": [
    {
      "js": [
        "katex/katex.min.js",
        "main.js"
      ],
      "matches": [
        "https://www.facebook.com/*"
      ]
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "katex/katex.min.css",
        "katex/fonts/*",
        "fb.katex.css"
      ],
      "matches": [
        "https://www.facebook.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@katex-for-messenger-web.ben-bavar"
    }
  }
}