feat: Turtle.TerDragonCurve ( Fixes #36 )

Author: James Brundage

Types/Turtle/TerdragonCurve.ps1

@@ -0,0 +1,31 @@
+
+<#
+.EXAMPLE
+    $turtle.TerdragonCurve().Pattern.Save("$pwd/TerdragonCurve.svg")
+.EXAMPLE
+    $turtle.Clear()
+    $turtle.TerdragonCurve(20,7,90)
+    $turtle.PatternTransform = @{
+        'scale' = 0.9
+        'rotate' = 45
+    }
+    
+    $turtle.PatternAnimation = "
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='scale' values='1;0.9;1' dur='19s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='skewY' values='30;-30;30' dur='67s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='skewX' values='30;-30;30' dur='83s' repeatCount='indefinite' additive='sum' />
+    "
+    $turtle.Pattern.Save("$pwd/TerdragonCurve2.svg")
+#>
+param(
+    [double]$Size = 20,
+    [int]$Order = 8,
+    [double]$Angle = 120
+)
+return $this.L('F',  [Ordered]@{
+    F = 'F+F-F'    
+}, $Order, [Ordered]@{
+    '\+'    = { $this.Rotate($Angle) }
+    '-'     = { $this.Rotate($Angle * -1) }
+    '[F]'  = { $this.Forward($Size) }
+})