Examine source code of Blocklive

{
  "name": "Blocklive: Scratch Realtime Collaboration",
  "description": "Multiple Scratchers Work together in Real Time on a Single Project",
  "version": "0.1.6.3",
  "icons": {
    "128": "icon128.png"
  },
  "manifest_version": 3,
  "content_scripts": [
    {
      "matches": [
        "https://scratch.mit.edu/projects*"
      ],
      "css": [],
      "js": [
        "injectors/editor.js"
      ]
    },
    {
      "matches": [
        "https://scratch.mit.edu/mystuff*"
      ],
      "css": [],
      "js": [
        "injectors/mystuff.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "/scripts/editor.js",
        "/scripts/vm.js",
        "/scripts/mystuff.js",
        "/scripts/turbowarp_editor.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "externally_connectable": {
    "matches": [
      "https://scratch.mit.edu/*"
    ]
  },
  "action": {
    "default_popup": "popups/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "meechapooch@gmail.com"
    }
  }
}