We explained earlier this year how to use a Nintendo Switch Pro controller on your PC, but it's kind of a laborious process, involving manually moving files around, extracting archives to specific locations, messing with DLLs, and other such eye-glazing guffola. Thankfully, a new update to the Steam client beta simplifies the situation for everyone by adding official support for the controller, including the gyro and d-pad.
You'll need to be in the Steam client beta if you want to give it a try: Click "Steam" in the upper-left corner of the client, then select "Settings" from the drop-down menu, and the "Change" button under the "Beta Participation" option on the Account page. (It's the top page in the menu, so it should be right in front of you.) Opt into the Steam Beta program, restart the program when prompted, and—possibly after a client update—you're set.
With that taken care of, the Nintendo Switch Pro controller will be available in the Controller page of the Settings menu. Checking the Switch Pro Configuration Support option will enable controller configurations to be created, shared, and browsed on a per-game basis; once it's selected, you can plug the controller in to your PC and register it when prompted. Valve recommends calibrating the controller manually to ensure that all is well with the gyro, after which you can create or load a controller configurations for individual games.
"The full functionality of the Steam Input Configurator is at your disposal: bind the gyro, add radial menus, create action sets, etc.," Valve said. "If you prefer to start from a community config, press X and browse the options."
After all that, it's finally time to launch your game. Controller configurations can be tweaked on the fly via the overlay, so it should be fairly easy to nail down exactly the setup you're after.
We don't have a lot of coverage of the Switch Pro controller here for obvious reasons, but with Steam support it may soon join the ranks of the best controllers for PC gaming.