remove number for source

src/recursion/recursion.go

@@ -0,0 +1,16 @@
+// ## Recursion
+
+package main
+
+import "fmt"
+
+func factorial(x uint) uint {
+    if x == 0 {
+        return 1
+    }
+    return x * factorial(x-1)
+}
+
+func main() {
+    fmt.Println(factorial(7))
+}