Examine source code of Pinned Gmail Switcher

{
  "manifest_version": 2,
  "name": "Pinned Gmail",
  "version": "1.0",
  "description": "Opens Gmail in a new pinned tab or switches to it if already open.",
  "developer": {
    "name": "Brook Seyoum",
    "url": "https://github.com/turmaxx"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9f2a6d10-3c4e-4f88-b1c2-7d9a8f5e1c22}",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "browser_action": {
    "default_title": "Gmail",
    "default_area": "navbar",
    "default_icon": {
      "48": "icons/gmail-icon.svg"
    }
  },
  "background": {
    "scripts": [
      "gmail.js"
    ]
  }
}