created directory for dialogs

src/widgets/dialogs/WelcomeDialog.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "widgets/BaseWindow.hpp"
+
+namespace chatterino {
+namespace widgets {
+
+class WelcomeDialog : public BaseWindow
+{
+public:
+    WelcomeDialog();
+};
+
+}  // namespace widgets
+}  // namespace chatterino