feat: Turtle.KochIsland() ( Fixes #49 )

Author: James Brundage

Types/Turtle/KochIsland.ps1

@@ -0,0 +1,36 @@
+<#
+.SYNOPSIS
+    Generates a Koch Island
+.DESCRIPTION
+    Generates a Koch Island using turtle graphics.   
+.EXAMPLE
+    $turtle.KochIsland().Pattern.Save("$pwd/KochIsland.svg")
+.EXAMPLE
+    $turtle.Clear()
+    $turtle.KochIsland(10,4)
+    $turtle.PatternTransform = @{
+        'scale' = 0.9        
+    }    
+    $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='0;-30;30;-30;0' dur='67s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='skewX' values='0;-30;30;-30;0' dur='83s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='rotate' values='0;360' dur='163s' repeatCount='indefinite' additive='sum' />
+    <animateTransform attributeName='patternTransform' attributeType='XML' type='translate' values='0 0;200 200;0 0' dur='283s' repeatCount='indefinite' additive='sum' />
+    "
+    $turtle.Pattern.Save("$pwd/KochIsland2.svg")
+#>
+param(
+    [double]$Size = 20,
+    [int]$Order = 3,
+    [double]$Angle = 90
+)
+
+return $this.LSystem('W',  [Ordered]@{
+    W = 'F+F+F+F'
+    F = 'F+F-F-FF+F+F-F'
+}, $Order, [Ordered]@{
+    '\+'    = { $this.Rotate($Angle) }
+    '-'     = { $this.Rotate($Angle * -1) }
+    '[FG]'  = { $this.Forward($Size) }
+})