move contexts all out in own toplevel dir

- rename wizard to book

pages/_app.tsx

@@ -1,5 +1,5 @@
 import '../styles/index.css'
-import UserContext from '../components/user/context'
+import UserContext from '../context/user'
 
 export default function MyApp({ Component, pageProps }) {
   const { username, role } = pageProps?.user || {}

pages/book.tsx

@@ -1,11 +1,11 @@
 import Layout from '../components/layout'
-import Wizard from '../components/wizard/index'
+import Book from '../components/book'
 
 export default function Home() {
   return (
     <Layout>
       <h1 className="mb-3 text-xl font-extrabold">Buchungsanfrage</h1>
-      <Wizard />
+      <Book />
     </Layout>
   )
 }