Mango Go Links
https://mangoumbrella.com/go/<KEY> is like a URL shortcut.
If you use desktop Chrome, you can add a new search engine with your preferred keyword (like go) and URL https://mangoumbrella.com/go/%s. Then just type go <KEY> in the address bar to use it.
Python Standard Library Shortcuts
This feature has graduated to a full project pyref.dev. In addition to Python's standard library, it also supports other popular PyPI packages.