placeholder for add node button

src/renderer/components/Experiment/Workflows/WorkflowCanvas.tsx

 import { Background, ControlButton, Controls, ReactFlow } from '@xyflow/react';
+import { PlusCircleIcon } from 'lucide-react';
 import React from 'react';
 
 function generateNodes(workflow: any) {
@@ -64,6 +65,11 @@ export default function WorkflowCanvas({ selectedWorkflow }) {
           *
         </ControlButton>
       </Controls>
+      <PlusCircleIcon
+        style={{ position: 'absolute', bottom: '20px', right: '20px' }}
+        strokeWidth={2}
+        size={32}
+      />
     </ReactFlow>
   );
 }

src/renderer/styles.css

@@ -215,4 +215,11 @@ textarea {
   margin: 0 5px 5px 0;
   font-size: 14px;
   font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif
+}
+
+/* React flow asks us not to hide attribution but it is
+MIT licensed so we have the right to modify the source
+code if we want */
+.react-flow__attribution a {
+  display: none;
 }
\ No newline at end of file