Examine source code of URL Envy

{
  "manifest_version": 2,
  "name": "URL Envy",
  "author": "Valera Fooksman",
  "description": "Allows editing the URL Params in the sidebar of the page.",
  "homepage_url": "https://github.com/oxfv/url_envy",
  "version": "1.0.3resigned1",
  "applications": {
    "gecko": {
      "id": "url_envy@nikak.net",
      "strict_min_version": "54.0a1"
    }
  },
  "sidebar_action": {
    "default_icon": "icons/url_envy-48.png",
    "default_title": "URL Envy",
    "default_panel": "sidebar/panel.html"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+U"
      }
    }
  }
}