Fix example in `NoiseTexture` doc

modules/opensimplex/doc_classes/NoiseTexture.xml

@@ -8,8 +8,9 @@
 		NoiseTexture can also generate normal map textures.
 		The class uses [Thread]s to generate the texture data internally, so [method Texture2D.get_image] may return [code]null[/code] if the generation process has not completed yet. In that case, you need to wait for the texture to be generated before accessing the image and the generated byte data:
 		[codeblock]
-		var texture = preload("res://noise.tres")
-		yield(texture, "changed")
+		var texture = NoiseTexture.new()
+		texture.noise = OpenSimplexNoise.new()
+		await texture.changed
 		var image = texture.get_image()
 		var data = image.get_data()
 		[/codeblock]