Add strict to randomNumber example

It is documented in the phpdoc but not in the examples.

readme.md

@@ -104,7 +104,7 @@ Each of the generator properties (like `name`, `address`, and `lorem`) are calle
 
     randomDigit             // 7
     randomDigitNotNull      // 5
-    randomNumber($nbDigits = NULL) // 79907610
+    randomNumber($nbDigits = NULL, $strict = false) // 79907610
     randomFloat($nbMaxDecimals = NULL, $min = 0, $max = NULL) // 48.8932
     numberBetween($min = 1000, $max = 9000) // 8567
     randomLetter            // 'b'