Alan turing portal (#815)

* [alan-turing-portal][m] - initial commit

* [alan-turing][m] - first page with search

* [alan-turing][m] - cleanup

examples/alan-turing-portal/pages/_app.jsx

@@ -0,0 +1,38 @@
+import { useEffect, useRef } from 'react'
+
+import { Footer } from '../components/Footer'
+import { Header } from '../components/Header'
+
+import '../styles/tailwind.css'
+import 'focus-visible'
+
+function usePrevious(value) {
+  let ref = useRef()
+
+  useEffect(() => {
+    ref.current = value
+  }, [value])
+
+  return ref.current
+}
+
+export default function App({ Component, pageProps, router }) {
+  let previousPathname = usePrevious(router.pathname)
+
+  return (
+    <>
+      <div className="fixed inset-0 flex justify-center sm:px-8">
+        <div className="flex w-full max-w-7xl lg:px-8">
+          <div className="w-full bg-white ring-1 ring-zinc-100 dark:bg-zinc-900 dark:ring-zinc-300/20" />
+        </div>
+      </div>
+      <div className="relative">
+        <Header />
+        <main>
+          <Component previousPathname={previousPathname} {...pageProps} />
+        </main>
+        <Footer />
+      </div>
+    </>
+  )
+}