Update docs for version 3.13.

CHANGES.txt

@@ -1,3 +1,13 @@
+Version 3.13 (14/02/2022)
+------------
+- Added curved line graph support with line_curve option.
+- Added horizontal 3D bar graph.
+- Added horizontal grouped 3D bar graph.
+- Added horizontal stacked 3D bar graph.
+- Added line_bar option for setting marker positions on bar and line graphs.
+- Cylinder graphs now support bar_top_overlay_* options.
+- Made conversion of multi-dataset data to structured more robust.
+
 Version 3.12 (10/12/2021)
 ------------
 - Added exploded semi-donut graph.

README.txt

@@ -1,4 +1,4 @@
-SVGGraph Library version 3.12
+SVGGraph Library version 3.13
 =============================
 
 This library provides PHP classes and functions for easily creating SVG
@@ -66,6 +66,12 @@ At the moment these types of graph are supported by SVGGraph:
 
  HorizontalGroupedBarGraph - a grouped bar graph drawn horizontally;
 
+ HorizontalBar3DGraph - a 3D bar graph with the axes swapped;
+
+ HorizontalStackedBar3DGraph - a stacked 3D bar graph drawn horizontally;
+
+ HorizontalGroupedBar3DGraph - a grouped 3D bar graph drawn horizontally;
+
  RadarGraph - a radar or star graph with values drawn as lines;
 
  MultiRadarGraph - a radar graph supporting multiple data sets;
@@ -323,4 +329,4 @@ For more information about this software please contact the author,
 graham(at)goat1000.com or visit the website: http://www.goat1000.com/
 
 
-Copyright (C) 2009-2021 Graham Breach
+Copyright (C) 2009-2022 Graham Breach