XML file not being imported

[mathuin]

I have a project https://github.com/mathuin/GravityTurn/tree/cleanup-csproj for which I am trying out Atom's IDE functionality with C#. The project includes a .csproj file https://github.com/mathuin/GravityTurn/blob/cleanup-csproj/GravityTurn/GravityTurn/GravityTurn.csproj This file includes a number of DLLs such as Assembly-CSharp.dll. When I build the project with msbuild, the resulting plugin works correctly.

I have downloaded Assembly-CSharp.xml https://raw.githubusercontent.com/Anatid/XML-Documentation-for-the-KSP-API/master/Assembly-CSharp.xml and placed it in the directory where the DLL is kept and restarted Atom. That file contains information on methods and attributes and classes and such, including a class named Orbit. When I open one of the .cs files with Atom, I see many errors and warnings from Omnisharp like this: "The type or namespace name 'Orbit' could not be found (are you missing a using directive or an assembly reference?)". I also do not get autocorrect or "intellisense" support for the objects in the XML file.