Added Point List Normal node

docs/user_guide/nodes/geometry/index.rst

@@ -5,5 +5,6 @@ Geometry
    :titlesonly:
 
    Convert Plane Type <convert_plane_type>
+   Point List Normal <point_list_normal>
 
 .. image:: images/geometry_overview.png

docs/user_guide/nodes/geometry/point_list_normal.rst

@@ -0,0 +1,37 @@
+Point List Normal
+=================
+
+Description
+-----------
+This node takes multiple vectors which represent points of a polygon and return the normal of that polygon.
+
+At least 3 points are needed to compute the normal. If more than 3 points were input, the resulted normal will be the average of the normals of each 3 points.
+
+.. image:: images/point_list_normal_node.png
+   :width: 160pt
+
+Inputs
+------
+
+- **Point List** - A vector list that contain the locations of the polygon points.
+
+Outputs
+-------
+
+- **Normal** - A unit vector that represent the normal of the polygon. A zero vector if points weren't valid.
+- **Is Valid** - A boolean which is True if blender was able to calculate the normal.
+
+Advanced Node Settings
+----------------------
+
+- N/A
+
+Notes
+-----
+
+The order of points matter as cross product is used to compute the normals, So points in reversed order will return a normal that is in the reverse direction of the normal computed by the original list.
+
+Examples of Usage
+-----------------
+
+.. image:: gifs/point_list_normal_node_example.gif