SphericalHarmonics3: Update type definitions.

src/math/SphericalHarmonics3.d.ts

@@ -10,6 +10,7 @@ export class SphericalHarmonics3 {
 	set ( coefficients: Vector3[] ): SphericalHarmonics3;
 	zero(): SphericalHarmonics3;
 	add( sh: SphericalHarmonics3 ): SphericalHarmonics3;
+	addScaledSH( sh: SphericalHarmonics3, s: number ): SphericalHarmonics3;
 	scale( s: number ): SphericalHarmonics3;
 	lerp( sh: SphericalHarmonics3, alpha: number ): SphericalHarmonics3;
 	equals( sh: SphericalHarmonics3 ): boolean;