All you need is a Bluetooth receiver on your PC to pair a Switch pro controller.
Getting controllers that weren't designed for PC to work on your PC has always been a bit of an issue. Microsoft has adopted a very plug-and-play approach in recent years, but Nintendo and Sony's offerings still require some tinkering, especially the Wii U pro controllers. However, it seems that with the Switch, PC functionality happens right out of the box, provided you have a Bluetooth receiver on your PC.
As demonstrated by YouTuber DreWoof, syncing your pro controller to your PC is as easy as opening up the Windows Bluetooth settings menu. Once synced, no additional software is required to use the controller with games. It reportedly functions with most games in Steam Big Picture mode, but some do not accept it.
It's worth noting that Bluetooth is the only way to sync your controller. Despite having a USB-C port for charging, you cannot sync up your controller using a USB cord.
DreWoof went on to further test the controller with other devices and programs. Android devices such as smartphones will apparently pair with the controller, but input can be laggy.