docs: Adds Dialogs Fiddle example (#20473)

docs/fiddles/native-ui/dialogs/save-dialog/renderer.js

@@ -0,0 +1,23 @@
+const { ipcRenderer, shell } = require('electron')
+
+const saveBtn = document.getElementById('save-dialog')
+const links = document.querySelectorAll('a[href]')
+
+saveBtn.addEventListener('click', event => {
+  ipcRenderer.send('save-dialog')
+})
+
+ipcRenderer.on('saved-file', (event, path) => {
+  if (!path) path = 'No path'
+  document.getElementById('file-saved').innerHTML = `Path selected: ${path}`
+})
+
+Array.prototype.forEach.call(links, (link) => {
+  const url = link.getAttribute('href')
+  if (url.indexOf('http') === 0) {
+    link.addEventListener('click', (e) => {
+      e.preventDefault()
+      shell.openExternal(url)
+    })
+  }
+})