[wpilib] Document simulation APIs (#3079)

- Remove sim checkstyle suppression
- Add [[nodiscard]] to C++ register callback functions
- Add a couple of missing sim functions

Co-authored-by: Peter Johnson <johnson.peter@gmail.com>
Co-authored-by: Starlight220 <yotamshlomi@gmail.com>

wpilibc/src/main/native/include/frc/simulation/GenericHIDSim.h

@@ -38,30 +38,101 @@ class GenericHIDSim {
    */
   void NotifyNewData();
 
+  /**
+   * Set the value of a given button.
+   *
+   * @param button the button to set
+   * @param value the new value
+   */
   void SetRawButton(int button, bool value);
 
+  /**
+   * Set the value of a given axis.
+   *
+   * @param axis the axis to set
+   * @param value the new value
+   */
   void SetRawAxis(int axis, double value);
 
+  /**
+   * Set the value of a given POV.
+   *
+   * @param pov the POV to set
+   * @param value the new value
+   */
   void SetPOV(int pov, int value);
 
+  /**
+   * Set the value of the default POV (port 0).
+   *
+   * @param value the new value
+   */
   void SetPOV(int value);
 
+  /**
+   * Set the axis count of this device.
+   *
+   * @param count the new axis count
+   */
   void SetAxisCount(int count);
 
+  /**
+   * Set the POV count of this device.
+   *
+   * @param count the new POV count
+   */
   void SetPOVCount(int count);
 
+  /**
+   * Set the button count of this device.
+   *
+   * @param count the new button count
+   */
   void SetButtonCount(int count);
 
+  /**
+   * Set the type of this device.
+   *
+   * @param type the new device type
+   */
   void SetType(GenericHID::HIDType type);
 
+  /**
+   * Set the name of this device.
+   *
+   * @param name the new device name
+   */
   void SetName(const char* name);
 
+  /**
+   * Set the type of an axis.
+   *
+   * @param axis the axis
+   * @param type the type
+   */
   void SetAxisType(int axis, int type);
 
+  /**
+   * Read the output of a button.
+   *
+   * @param outputNumber the button number
+   * @return the value of the button (true = pressed)
+   */
   bool GetOutput(int outputNumber);
 
+  /**
+   * Get the encoded 16-bit integer that passes button values.
+   *
+   * @return the button values
+   */
   int64_t GetOutputs();
 
+  /**
+   * Get the joystick rumble.
+   *
+   * @param type the rumble to read
+   * @return the rumble value
+   */
   double GetRumble(GenericHID::RumbleType type);
 
  protected: