Added RelayNodeView;

Chnaged GraphView to multiple files for better organization;

Editor/Views/GraphView/GraphView_ContextualMenu.cs

@@ -0,0 +1,45 @@
+using UnityEditor.Experimental.GraphView;
+using UnityEngine;
+using UnityEngine.UIElements;
+
+namespace Misaki.GraphView.Editor
+{
+    public partial class GraphView
+    {
+        public override void BuildContextualMenu(ContextualMenuPopulateEvent evt)
+        {
+            base.BuildContextualMenu(evt);
+            var mousePosition = (evt.currentTarget as VisualElement).ChangeCoordinatesTo(contentViewContainer, evt.localMousePosition);
+
+            if (evt.target is GraphView)
+            {
+                evt.menu.InsertAction(1, "Create Sticky Note", e =>
+                {
+                    var stickyNote = new StickyNoteData
+                    {
+                        title = "Sticky Note",
+                        contents = "Contents",
+                        theme = StickyNoteTheme.Classic,
+                        fontSize = StickyNoteFontSize.Medium,
+                        position = new Rect(mousePosition, new Vector2(200, 200))
+                    };
+
+                    AddStickyNote(stickyNote);
+                }, DropdownMenuAction.AlwaysEnabled);
+            }
+
+            if (evt.target is Edge)
+            {
+                evt.menu.AppendAction("Create Relay Node", e =>
+                {
+                    var relayNode = new RelayNode
+                    {
+                        position = new Rect(mousePosition, Vector2.zero)
+                    };
+
+                    AddRelayNode(relayNode);
+                }, DropdownMenuAction.AlwaysEnabled);
+            }
+        }
+    }
+}