(DOCSP-12752) Opacity and stroke thickness for scatter charts (#434)

* (DOCSP-12752) Opacity and stroke thickness for scatter charts

Author: zach-carr

source/chart-type-reference/scatter-chart.txt

@@ -97,6 +97,21 @@ Customization Options
 The following customization options are specific to scatter charts. To
 see all available customization options, see :ref:`customize-charts`.
 
+Opacity
+~~~~~~~
+
+The :guilabel:`Opacity` customization option, measured as a 
+percentage, modifies the transparency of the data point fill. This 
+setting defaults to ``0%``, which renders the data point fill as 
+completely transparent.
+
+Stroke Thickness
+~~~~~~~~~~~~~~~~
+
+The :guilabel:`Stroke Thickness` customization option, measured in 
+pixels, modifies the thickness of data point outlines. This setting 
+defaults to ``2``.
+
 .. _customize-scatter-marks:
 
 Mark Size