fix: Move content into to frontend directory

Doing this BEFORE the merge prevents a lot of merge conflicts.

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/src/components/landing-layout/landing-layout.tsx

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import type { PropsWithChildren } from 'react'
+import React, { Fragment } from 'react'
+import { Container } from 'react-bootstrap'
+import { MotdModal } from '../common/motd-modal/motd-modal'
+import { Footer } from './footer/footer'
+import { HeaderBar } from './navigation/header-bar/header-bar'
+
+/**
+ * Renders the layout for both intro and history page.
+ *
+ * @param children The children that should be rendered on the page.
+ */
+export const LandingLayout: React.FC<PropsWithChildren<unknown>> = ({ children }) => {
+  return (
+    <Fragment>
+      <MotdModal />
+      <Container className='text-light d-flex flex-column mvh-100'>
+        <HeaderBar />
+        <div className={'d-flex flex-column justify-content-between flex-fill text-center'}>
+          <main>{children}</main>
+          <Footer />
+        </div>
+      </Container>
+    </Fragment>
+  )
+}