MacOS already has similar functionality
It should be noted that you can already do this with MacOS. Almost all commands with their respective keyboard shortcuts are listed in the menu bar for each app, and can be searched through using the Help tab (Command + Shift + /).
More info: https://apple.stackexchange.com/a/11673
That said, nothing exists on Windows that can do this yet, so I'm really eager to try this product out there!