Fixed typos.

Author: lizlooney

external_samples/docs/sparkfun_led_stick.md

@@ -2,12 +2,12 @@
 
 <img src="SparkFunLEDStick_set_color_1.png">
 
-<img src="SparkFunLEDStock_set_brightness_1.png">
+<img src="SparkFunLEDStick_set_brightness_1.png">
 
-<img src="SparkFunLEDStock_set_brightness_2.png">
+<img src="SparkFunLEDStick_set_brightness_2.png">
 
-<img src="SparkFunLEDStock_set_color_2.png">
+<img src="SparkFunLEDStick_set_color_2.png">
 
-<img src="SparkFunLEDStock_set_colors.png">
+<img src="SparkFunLEDStick_set_colors.png">
 
-<img src="SparkFunLEDStock_turn_all_off.png">
+<img src="SparkFunLEDStick_turn_all_off.png">