add basic vite setup

demos/setup/helper.ts

@@ -0,0 +1,38 @@
+const waitUntilElementExists = (selector: any, callback: (element: Element) => void) => {
+  const element = document.querySelector(selector)
+
+  if (element) {
+    return callback(element)
+  }
+
+  setTimeout(() => waitUntilElementExists(selector, callback), 500)
+}
+
+const sendData = (eventName: string, data: any) => {
+  const event = new CustomEvent(eventName, { detail: data })
+
+  window.parent.document.dispatchEvent(event)
+}
+
+export function splitName(name: string) {
+  const parts = name.split('/')
+
+  if (parts.length !== 2) {
+    throw Error('Demos must always be within exactly one category. Nested categories are not supported.')
+  }
+
+  return parts
+}
+
+export function debug() {
+  sendData('editor', null)
+  // @ts-ignore
+  sendData('source', window.source)
+
+  waitUntilElementExists('.ProseMirror', element => {
+    // @ts-ignore
+    const editor = element.editor
+
+    sendData('editor', editor)
+  })
+}