feat: set up interface splitter

src/gui/Interface.h

@@ -1,11 +1,18 @@
 #pragma once
 #include <QWidget>
+#include <QBoxLayout>
+#include <QSplitter>
 
 class EnzoUI
 : public QWidget
 {
     public:
+        EnzoUI(); 
         
     private:
+        QVBoxLayout* mainLayout_;
+        QVBoxLayout* viewportSplitLayout_;
+        QSplitter* viewportSplitter_;
+
 
 };