Examine source code of Reading List

{
  "applications": {
    "gecko": {
      "id": "readinglist@waldemar.b",
      "strict_min_version": "60.0a1"
    }
  },
  "permissions" : [
    "tabs" ,
    "storage" ,
    "<all_urls>" ,
    "contextMenus" ,
    "notifications" ,
    "bookmarks" 
  ],
  "sidebar_action": {
    "browser_style": false,
    "default_title" : "__MSG_extensionName__" ,
    "default_panel": "sidebar.html",
    "default_icon" : "icons/icon.svg"
  },
  "browser_action" : {
    "default_title" : "__MSG_extensionAction__" ,
    "default_icon" : "icons/btn.svg#dark",
    "theme_icons": [
      {
        "light": "icons/btn.svg#light",
        "dark": "icons/btn.svg#dark",
        "size": 19
      }
    ]
  },
  "page_action" : {
    "default_icon" : {
      "19" : "icons/btn.svg#dark"
    }
  },
  "background" : {
    "page": "bg.html"
  },
  "commands" : {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Q",
        "mac": "Alt+R",
        "linux": "Alt+R"
      }
    }
  },
  "description" : "__MSG_extensionDescription__" ,
  "manifest_version" : 2 ,
  "default_locale" : "en" ,
  "name" : "__MSG_extensionName__" ,
  "version" : "1.5.5",
  "icons" : {
    "48" : "icons/icon.svg"
  },
  "options_ui" : {
    "browser_style": false,
    "page": "/index.html#options" ,
    "open_in_tab": true
  }
}