docs: add app information example (#20487)

* docs: add app information example

* Code review changes

* Remove demo-control css class, link href change

docs/fiddles/system/system-app-user-information/app-information/renderer.js

@@ -0,0 +1,18 @@
+const {ipcRenderer} = require('electron')
+
+const appInfoBtn = document.getElementById('app-info')
+const electron_doc_link = document.querySelectorAll('a[href]')
+
+appInfoBtn.addEventListener('click', () => {
+  ipcRenderer.send('get-app-path')
+})
+
+ipcRenderer.on('got-app-path', (event, path) => {
+  const message = `This app is located at: ${path}`
+  document.getElementById('got-app-info').innerHTML = message
+})
+
+electron_doc_link.addEventListener('click', (e) => {
+  e.preventDefault()
+  shell.openExternal(url)
+})