Open the Package Manager, click on the + Icon, select "Add Package from Git Url".
Enter the package url: git@github.com:FredMoreau/com.unity.shader-globals.git
Open the Project Settings
Select the Graphics / Shader Globals tab.
You can add your global values here.
They will immediatly apply in the Editor.
At runtime, they will be set upon load so that other C# scripts can still override them.