Quick bit of news for you: Steam now supports Nintendo Switch's Joy-Con controllers.
Support was added by Valve via the latest Steam Client Beta which was released earlier this week.
The update supports the controllers both individually as a mini-gamepad and combined into pairs.
It also adds improved support for the Nintendo Online classic controllers, added back in June.
If you want to try the feature out, you will need to be part of the Steam beta. If you plan to use the controllers, your PC needs a motherboard that supports Bluetooth or alternatively, you can use a Bluetooth adapter like this one from Asus, for example.