fix: Integrate LED1 init into callback step.

Author: AnnsAnns

doc/guides/c_tutorials/gpio.mdx

@@ -181,12 +181,6 @@ that way we can drastically reduce the power consumption of the device.
 First we need to define the callback function
 that will be called when the button is pressed.
 
-```c title="Define the LED1 pin and mode"
-/* Define the LED1 pin and mode */
-gpio_t led1 = GPIO_PIN(1, 10);
-gpio_mode_t led1_mode = GPIO_OUT;
-```
-
 ```c title="Define the button callback function"
 /* This callback function will be called when the button state changes */
 void button_callback(void *arg) {
@@ -202,9 +196,13 @@ void button_callback(void *arg) {
 }
 ```
 
-Now we need to define the button pin and mode and initialize it.
+Now we need to define the button and led1 pin and mode and initialize it.
+
+```c {1-6, 27-33}
+/* Define the LED1 pin and mode */
+gpio_t led1 = GPIO_PIN(1, 10);
+gpio_mode_t led1_mode = GPIO_OUT;
 
-```c {1-2, 26-27}
 /* Define the button pin */
 gpio_t button = GPIO_PIN(1, 2);