Remove undefined from demo

Author: CarlosNZ

demo/src/demoData/data.tsx

@@ -4,7 +4,6 @@ export const data: Record<string, object> = {
     number: 99,
     boolean: true,
     nothing: null,
-    undefined: undefined,
     Usage: [
       'Edit a value by clicking the "edit" icon, or double-clicking the value.',
       'You can change the type of any value',

demo/src/demoData/dataDefinitions.tsx

@@ -25,7 +25,6 @@ import { Input } from 'object-property-assigner/build'
 import jsonSchema from './jsonSchema.json'
 import customNodesSchema from './customNodesSchema.json'
 import Ajv from 'ajv'
-import { undefinedNodeDefinition } from '../customComponents/Undefined'
 
 const ajv = new Ajv()
 const validateJsonSchema = ajv.compile(jsonSchema)
@@ -91,7 +90,7 @@ export const demoDataDefinitions: Record<string, DemoData> = {
     rootName: 'data',
     collapse: 2,
     data: data.intro,
-    customNodeDefinitions: [dateNodeDefinition, undefinedNodeDefinition],
+    customNodeDefinitions: [dateNodeDefinition],
   },
   starWars: {
     name: '🚀 Star Wars',