Move visual shaders to a module

modules/visual_shader/doc_classes/VisualShaderNodeVectorRefract.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="VisualShaderNodeVectorRefract" inherits="VisualShaderNodeVectorBase" api_type="core" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
+	<brief_description>
+		Returns the vector that points in the direction of refraction. For use within the visual shader graph.
+	</brief_description>
+	<description>
+		Translated to [code]refract(I, N, eta)[/code] in the shader language, where [code]I[/code] is the incident vector, [code]N[/code] is the normal vector and [code]eta[/code] is the ratio of the indices of the refraction.
+	</description>
+	<tutorials>
+	</tutorials>
+</class>