Added small comment on GPIO.

src/gpio/gpiobasic.hpp

@@ -22,6 +22,11 @@
 #include "sdkwrapper.hpp"
 
 namespace rpp_driver {
+/**
+ * @brief Basic GPIO driver class.
+ * @details
+ * This class provide very basic operation of GPIO.
+ */
 class GpioBasic {
  public:
   /**