[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/AnalogTriggerSim.h

@@ -45,27 +45,86 @@ class AnalogTriggerSim {
    */
   static AnalogTriggerSim CreateForIndex(int index);
 
-  std::unique_ptr<CallbackStore> RegisterInitializedCallback(
+  /**
+   * Register a callback on whether the analog trigger is initialized.
+   *
+   * @param callback the callback that will be called whenever the analog
+   *                 trigger is initialized
+   * @param initialNotify if true, the callback will be run on the initial value
+   * @return the CallbackStore object associated with this callback
+   */
+  [[nodiscard]] std::unique_ptr<CallbackStore> RegisterInitializedCallback(
       NotifyCallback callback, bool initialNotify);
 
+  /**
+   * Check if this analog trigger has been initialized.
+   *
+   * @return true if initialized
+   */
   bool GetInitialized() const;
 
+  /**
+   * Change whether this analog trigger has been initialized.
+   *
+   * @param initialized the new value
+   */
   void SetInitialized(bool initialized);
 
-  std::unique_ptr<CallbackStore> RegisterTriggerLowerBoundCallback(
-      NotifyCallback callback, bool initialNotify);
+  /**
+   * Register a callback on the lower bound.
+   *
+   * @param callback the callback that will be called whenever the lower bound
+   *                 is changed
+   * @param initialNotify if true, the callback will be run on the initial value
+   * @return the CallbackStore object associated with this callback
+   */
+  [[nodiscard]] std::unique_ptr<CallbackStore>
+  RegisterTriggerLowerBoundCallback(NotifyCallback callback,
+                                    bool initialNotify);
 
+  /**
+   * Get the lower bound.
+   *
+   * @return the lower bound
+   */
   double GetTriggerLowerBound() const;
 
+  /**
+   * Change the lower bound.
+   *
+   * @param triggerLowerBound the new lower bound
+   */
   void SetTriggerLowerBound(double triggerLowerBound);
 
-  std::unique_ptr<CallbackStore> RegisterTriggerUpperBoundCallback(
-      NotifyCallback callback, bool initialNotify);
+  /**
+   * Register a callback on the upper bound.
+   *
+   * @param callback the callback that will be called whenever the upper bound
+   *                 is changed
+   * @param initialNotify if true, the callback will be run on the initial value
+   * @return the CallbackStore object associated with this callback
+   */
+  [[nodiscard]] std::unique_ptr<CallbackStore>
+  RegisterTriggerUpperBoundCallback(NotifyCallback callback,
+                                    bool initialNotify);
 
+  /**
+   * Get the upper bound.
+   *
+   * @return the upper bound
+   */
   double GetTriggerUpperBound() const;
 
+  /**
+   * Change the upper bound.
+   *
+   * @param triggerUpperBound the new upper bound
+   */
   void SetTriggerUpperBound(double triggerUpperBound);
 
+  /**
+   * Reset all simulation data for this object.
+   */
   void ResetData();
 
  private: