How do I add grid lines to a material?,How do you add grid lines to a material?

I’m trying to create a new material and I want it to have the grid lines like the environment in a video I saw ( FIRST PERSON MOVEMENT in Unity - FPS Controller - YouTube ). Does anyone know how to do this?

Watch this video: MAKING YOUR FIRST LEVEL in Unity with ProBuilder! - YouTube
He explains pro builder (Which he used to make that level)
Pro builder comes with that grid pattern.