Updated Defining custom lightings (markdown)

Defining-custom-lightings.md

@@ -14,6 +14,7 @@ A typical lighting configuration is shown below:
         shadowstrength: 1.0
         ambientlight: 4
         night-and-day: true
+        smooth-lighting: false
 
 The settings defined for the ShadowHDLighting class include the following:
 
@@ -25,4 +26,5 @@ The settings defined for the ShadowHDLighting class include the following:
 
 - _night-and-day_ : Enabling this setting (by setting the value to **true**) results in the generation of both night and day versions of each tile, and in the map view automatically switching between them, based on the time-of-day of the corresponding world.  The difference between the 'night' tiles and the 'day' tiles is that the day tiles are rendered with _ambientlight_ set to 15, while the night tiles use the provided _ambientlight_ setting.  The default value is **false**.
 
+* _smooth-lighting_ : this setting, a boolean, controls the enabling of the smooth lighting option.  Enabling this feature will add approximately 10% to rendering processing cost, but will result in much smoother shadows and lighting.  If not defined, the _smooth-lighting_ setting from _configuration.txt_ is used.