[examples] Update Command-based starter project (#4778)

wpilibcExamples/src/main/cpp/templates/commandbased/include/subsystems/ExampleSubsystem.h

@@ -4,12 +4,18 @@
 
 #pragma once
 
+#include <frc2/command/CommandPtr.h>
 #include <frc2/command/SubsystemBase.h>
 
 class ExampleSubsystem : public frc2::SubsystemBase {
  public:
   ExampleSubsystem();
 
+  /**
+   * Example command factory method.
+   */
+  frc2::CommandPtr ExampleMethodCommand();
+
   /**
    * Will be called periodically whenever the CommandScheduler runs.
    */