Get Atom to go to the correct line when opening a file from Unity
Get the app or contribute on github.
Make sure that the Atom.cs file is placed under an Editor folder in the project. A good place would be in /Assets/Plugins/Editor/Atom.cs.
Once the Atom file is in place, go to Unity Preferences -> External Tools -> External Script Editor and select your Atom installation.
Most of this comes from the VSCode project by dotBunny.