Updated Bag of Tricks (markdown)

Bag-of-Tricks.md

@@ -1,5 +1,29 @@
 Here are helper class that can help you add missing features.
 
+## Extract an array of integer
+
+Suppose we have an input like this:
+
+```json
+{"leds":[56,60,46]}
+```
+
+And we want to get a `int[]` out of it:
+
+```c++
+#define MAX_LED_COUNT 10
+
+int leds[MAX_LED_COUNT];
+int ledCount = 0;
+
+for(int led : root["leds"].asArray()) {
+    leds[ledCount++] = led;
+    if (ledCount >= MAX_LED_COUNT) break;
+}
+```
+
+See issue [#246](https://github.com/bblanchon/ArduinoJson/issues/246)
+
 ## Buffered output:
 
 Here is a proxy that will put bytes in a buffer before actually writing them to the destination: