Examine source code of Tabs2Text

{
  "applications": {
    "gecko": {
      "strict_min_version": "58.0",
      "id": "tabs2text@github.deniszanin"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "58.0"
    }
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icons/t2f-ico.svg",
      "32": "icons/t2f-ico.svg",
      "48": "icons/t2f-ico.svg",
      "96": "icons/t2f-ico.svg"
    },
    "default_popup": "tabs2text-popup.html",
    "default_title": "Tabs2Text"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "commands": {
    "t2t-export": {
      "suggested_key": {
        "default": "Ctrl+Shift+U",
        "chromeos": "Ctrl+Shift+U",
        "linux": "Ctrl+Shift+U",
        "mac": "Command+Shift+U",
        "windows": "Ctrl+Shift+U"
      },
      "description": "__MSG_commandDesc__"
    }
  },
  "default_locale": "en",
  "description": "__MSG_appDesc__",
  "homepage_url": "https://github.com/deniszanin/tabs2text",
  "icons": {
    "16": "icons/t2f-ico.svg",
    "32": "icons/t2f-ico.svg",
    "48": "icons/t2f-ico.svg",
    "96": "icons/t2f-ico.svg",
    "128": "icons/t2f-ico.svg"
  },
  "incognito": "spanning",
  "manifest_version": 2,
  "name": "Tabs2Text",
  "options_ui": {
    "page": "tabs2text-settings.html"
  },
  "permissions": [
    "tabs",
    "downloads",
    "storage"
  ],
  "version": "2020.6.11"
}