Examine source code of Gmail Notepad

{
  "manifest_version": 3,
  "name": "Gmail Notepad",
  "version": "1.1",
  "description": "Attach persistent notes to Gmail email threads.",
  "permissions": [
    "storage",
    "tabs"
  ],
  "host_permissions": [
    "https://mail.google.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "src/shared/constants.js",
        "src/content/storage.js",
        "src/content/thread-detector.js",
        "src/content/note-cache.js",
        "src/content/thread-id.js",
        "src/content/thread-view.js",
        "src/content/list-view.js",
        "src/content/content.js"
      ],
      "css": [
        "styles/panel.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "service_worker": "src/background.js",
    "scripts": [
      "src/background.js"
    ]
  },
  "action": {
    "default_popup": "src/popup/popup.html",
    "default_title": "Gmail Notepad",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "styles/panel.css"
      ],
      "matches": [
        "https://mail.google.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{90b7af37-981b-4118-bdcc-639b235b10b3}",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}