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/common/pagination/pager-item.tsx

@@ -0,0 +1,28 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import React from 'react'
+
+export interface PageItemProps {
+  onClick: (index: number) => void
+  index: number
+}
+
+/**
+ * Renders a number and adds an onClick handler to it.
+ *
+ * @param index The number to render
+ * @param onClick The onClick Handler
+ */
+export const PagerItem: React.FC<PageItemProps> = ({ index, onClick }) => {
+  return (
+    <li className='page-item'>
+      <span className='page-link' role='button' onClick={() => onClick(index)}>
+        {index + 1}
+      </span>
+    </li>
+  )
+}