Added Shell sort

sorting/shell_sort.go

@@ -0,0 +1,25 @@
+package main
+
+/*
+ * Shell sort - http://en.wikipedia.org/wiki/Shellsort
+ */
+
+import "fmt"
+
+import "github.com/0xAX/go-algorithms"
+
+func main() {
+	arr := utils.RandArray(10)
+    fmt.Println("Initial array is:", arr)
+    fmt.Println("")
+
+    for d := int(len(arr)/2); d > 0; d /= 2 {
+    	for i := d; i < len(arr); i++ {
+    		for j := i; j >= d && arr[j-d] > arr[j]; j -= d {
+    			arr[j], arr[j-d] = arr[j-d], arr[j]
+    		}
+    	}
+    }
+
+    fmt.Println("Sorted array is: ", arr) 	
+}