adding requirement information for triangle point

triangle point in linebar chart

@@ -8,7 +8,8 @@
 typedef NS_ENUM(NSUInteger, PNLineChartPointStyle) {
     PNLineChartPointStyleNone = 0,
     PNLineChartPointStyleCircle = 1,
-    PNLineChartPointStyleSquare = 3
+    PNLineChartPointStyleSquare = 3,
+    PNLineChartPointStyleTriangle = 4
 };
 
 @class PNLineChartDataItem;

@@ -38,7 +38,7 @@
         PNLineChartData *data01 = [PNLineChartData new];
         data01.color = PNFreshGreen;
         data01.itemCount = lineChart.xLabels.count;
-        data01.inflexionPointStyle = PNLineChartPointStyleCircle;
+        data01.inflexionPointStyle = PNLineChartPointStyleTriangle;
         data01.getData = ^(NSUInteger index) {
             CGFloat yValue = [data01Array[index] floatValue];
             return [PNLineChartDataItem dataItemWithY:yValue];