add choose

docs/lib2x-choose.md

@@ -0,0 +1,16 @@
+# choose
+
+Choose an element from the given list randomly.
+
+**Since:** 2.5
+
+## Parameters
+
+- `choices` : The list to choose from.
+- `seed` : Random seed value.
+
+## Examples
+
+    use <util/choose.scad>;
+    
+    echo(choose([1, 2, 3, 4]));