Move this over to a manual example

[schell]

Tests the initial implementation of pbr metallic roughness on an array of
spheres with different metallic roughnesses lit by an environment map.
see https://learnopengl.com/PBR/Lighting

renderling/crates/renderling/src/pbr.rs

Lines 24 to 28 in 9b51846

	// TODO: Move this over to a manual example
	// Tests the initial implementation of pbr metallic roughness on an array of
	// spheres with different metallic roughnesses lit by an environment map.
	//
	// see https://learnopengl.com/PBR/Lighting