Clarified the expected sensor value when a game controller is at rest (cherry picked from commit 1a20ccb2897fc9b12ad5242f9128cb6bb60368b1)
diff --git a/include/SDL_sensor.h b/include/SDL_sensor.h
index 3010e49..9ecce44 100644
--- a/include/SDL_sensor.h
+++ b/include/SDL_sensor.h
@@ -84,7 +84,7 @@ typedef enum
* The accelerometer returns the current acceleration in SI meters per
* second squared. This measurement includes the force of gravity, so
* a device at rest will have an value of SDL_STANDARD_GRAVITY away
- * from the center of the earth.
+ * from the center of the earth, which is a positive Y value.
*
* values[0]: Acceleration on the x axis
* values[1]: Acceleration on the y axis