Nintendo Switch Joy-Cons coming to PC: Valve supported controls
To use them, you need to use the Steam beta client.

The Steam platform continues to open and expand its borders. This time he accomplished something that many fans will be surprised by. valve added Support for Joy-Con According to an update on the Steam blog, you can now play various games with small controllers.
To use Joy-Con, you need access to the Steam beta client.Currently this is only possible You have a Steam beta client. You can easily get it by following the steps on the official Steam beta client website. Also, it has Improved compatibility with classic Nintendo Online controllers.
The Steam post states the following regarding the Joy-Con: “Added Joy-Con controller compatibility Nintendo both individually as a minigamepad and in pairs”. Play with one or both of the Joy-Con.
Last month, Valve already announced support for Nintendo Online’s classic controls. These: NES, SNES, Nintendo 64 and SEGA Mega Drive and Genesis. Now the latest addition of Joy-Con is great news to increase the possibilities to play despite the drags.
More on: Nintendo Switch, Joy-con and Steam.
Source: 3D Juegos