doc: updated example

README.md

@@ -49,8 +49,6 @@ void app_main(void)
     config.triac_gpio = GPIO_NUM_17;
     zh_ac_dimmer_init(&config);
     zh_ac_dimmer_start();
-    for (;;)
-    {
     for (uint8_t i = 0; i <= 100; ++i)
     {
         zh_ac_dimmer_set(i);
@@ -61,6 +59,7 @@ void app_main(void)
         zh_ac_dimmer_set(i);
         vTaskDelay(100 / portTICK_PERIOD_MS);
     }
-    }
+    zh_ac_dimmer_stop();
+    zh_ac_dimmer_deinit();
 }
 ```