feat: Turtle.get_Minimum ( Fixes #9 )

Author: James Brundage

Types/Turtle/get_Minimum.ps1

@@ -0,0 +1,4 @@
+if ($this.'.Minimum') {
+    return $this.'.Minimum'
+}
+return ([pscustomobject]@{ X = 0; Y = 0 })