Examine source code of Pimp My X

{
  "manifest_version": 3,
  "name": "Pimp My X",
  "version": "0.0.1",
  "description": "Pimp UI/UX of X.com",
  "permissions": [],
  "host_permissions": [
    "https://*.x.com/*",
    "https://x.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.x.com/*",
        "https://x.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Pimp My X"
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png",
    "256": "icons/icon-256.png",
    "512": "icons/icon-512.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@pimp-my-x",
      "strict_min_version": "58.0"
    }
  }
}