Add example about std.parallelism

index.dd

@@ -142,6 +142,25 @@ void main()
 }
 ----
 )
+$(EXTRA_EXAMPLE_RUNNABLE Initialize an Array in parallel,
+----
+void main()
+{
+    import std.datetime, std.math, std.parallelism, std.stdio;
+
+    auto logs = new double[100_000];
+    auto bm = benchmark!({
+        foreach (i, ref elem; logs)
+            elem = log(1.0 + i);
+    }, {
+        foreach (i, ref elem; logs.parallel)
+            elem = log(1.0 + i);
+    })(100); // number of executions of each tested function
+    writefln("Linear init: %s msecs", bm[0].msecs);
+    writefln("Parallel init: %s msecs", bm[1].msecs);
+}
+----
+)
 
 ) $(COMMENT your-code-here)
 ))) $(COMMENT intro, div, div)