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/pages/intro.tsx

@@ -0,0 +1,46 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import type { NextPage } from 'next'
+import { LandingLayout } from '../components/landing-layout/landing-layout'
+import { EditorToRendererCommunicatorContextProvider } from '../components/editor-page/render-context/editor-to-renderer-communicator-context-provider'
+import {
+  HedgeDocLogoSize,
+  HedgeDocLogoType,
+  HedgeDocLogoWithText
+} from '../components/common/hedge-doc-logo/hedge-doc-logo-with-text'
+import { Trans } from 'react-i18next'
+import { Branding } from '../components/common/branding/branding'
+import { CoverButtons } from '../components/intro-page/cover-buttons/cover-buttons'
+import React from 'react'
+import { IntroCustomContent } from '../components/intro-page/intro-custom-content'
+
+/**
+ * Renders the intro page with the logo and the customizable intro text.
+ */
+const IntroPage: NextPage = () => {
+  return (
+    <LandingLayout>
+      <EditorToRendererCommunicatorContextProvider>
+        <div className={'flex-fill mt-3'}>
+          <h1 dir='auto' className={'align-items-center d-flex justify-content-center flex-column'}>
+            <HedgeDocLogoWithText logoType={HedgeDocLogoType.COLOR_VERTICAL} size={HedgeDocLogoSize.BIG} />
+          </h1>
+          <p className='lead'>
+            <Trans i18nKey='app.slogan' />
+          </p>
+          <div className={'mb-5'}>
+            <Branding delimiter={false} />
+          </div>
+          <CoverButtons />
+          <IntroCustomContent />
+          <hr className={'mb-5'} />
+        </div>
+      </EditorToRendererCommunicatorContextProvider>
+    </LandingLayout>
+  )
+}
+
+export default IntroPage