Monitor utilites (#1485)

* Added a new utility function to get the current monitor.

Some of the other functions rely on passing on a monitor id but we only have a function for querying the count of monitors available.

* Updated the comment to correctly reflect the function action

src/core.c

@@ -1452,6 +1452,16 @@ int GetMonitorCount(void)
 #endif
 }
 
+// Get number of monitors
+int GetCurrentMonitor(void)
+{
+#if defined(PLATFORM_DESKTOP)
+    return glfwGetWindowMonitor(CORE.Window.handle);
+#else
+    return 0;
+#endif
+}
+
 // Get selected monitor width
 Vector2 GetMonitorPosition(int monitor)
 {

src/raylib.h

@@ -916,6 +916,7 @@ RLAPI void *GetWindowHandle(void);                                // Get native
 RLAPI int GetScreenWidth(void);                                   // Get current screen width
 RLAPI int GetScreenHeight(void);                                  // Get current screen height
 RLAPI int GetMonitorCount(void);                                  // Get number of connected monitors
+RLAPI int GetCurrentMonitor(void);                                // Get current connected monitor
 RLAPI Vector2 GetMonitorPosition(int monitor);                    // Get specified monitor position
 RLAPI int GetMonitorWidth(int monitor);                           // Get specified monitor width
 RLAPI int GetMonitorHeight(int monitor);                          // Get specified monitor height