Docs for some nodes in visual shader(part 3)

doc/classes/VisualShaderNodeFloatConstant.xml

@@ -1,8 +1,10 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <class name="VisualShaderNodeFloatConstant" inherits="VisualShaderNode" version="4.0">
 	<brief_description>
+		A scalar floating-point constant to be used within the visual shader graph.
 	</brief_description>
 	<description>
+		Translated to [code]float[/code] in the shader language.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -10,6 +12,7 @@
 	</methods>
 	<members>
 		<member name="constant" type="float" setter="set_constant" getter="get_constant" default="0.0">
+			A floating-point constant which represents a state of this node.
 		</member>
 	</members>
 	<constants>