Examine source code of Tab Grid

{
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "59.0",
      "id": "{a33dac77-4b4f-48db-a03b-55ed1fdbe3ff}"
    }
  },
  "background": {
    "scripts": [
      "scripts-dist/background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_title": "Tab Grid",
    "default_popup": "popup.html"
  },
  "description": "An extension for lovely people that want to clean up their tabs",
  "homepage_url": "https://gitlab.com/DrTexx/tab-grid",
  "manifest_version": 2,
  "name": "Tab Grid",
  "permissions": [
    "tabs",
    "<all_urls>",
    "sessions",
    "storage"
  ],
  "version": "1.0.1"
}