You can't do that. It's more a licensing issue. If you could put/enable everything in the isolated shell, then nobody would buy Visual Studio anymore.

Here is a more official answer from here: How to connect C# VSPackage to Visual Studio Shell Isolated Mode to have syntax highlighting

VS languages like C#, VB, and C++ cannot be loaded in the isolated shell. Hence the reason we call it isolated :-)

Additionally it should be noted, the integrated shell does not include these packages, nor are they licensed for redistribution; as they are distributed with the Visual Studio product.

The integrated shell is basically the core VS IDE, wherease the isolated shell is essentially the same IDE, but runs using a different stub application (so you can customize it to suite your needs). But the isolated shell does not ship with, or will it load any of the mainstream language/project services that ship with VS Pro.