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/editor-page/sidebar/specific-sidebar-entries/share-sidebar-entry.tsx

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import React, { Fragment } from 'react'
+import { Trans, useTranslation } from 'react-i18next'
+import { ShareModal } from '../../document-bar/share/share-modal'
+import { SidebarButton } from '../sidebar-button/sidebar-button'
+import type { SpecificSidebarEntryProps } from '../types'
+import { useBooleanState } from '../../../../hooks/common/use-boolean-state'
+
+/**
+ * Renders a button to open the share modal for the sidebar.
+ *
+ * @param className Additional classes directly given to the button
+ * @param hide If the button should be hidden
+ */
+export const ShareSidebarEntry: React.FC<SpecificSidebarEntryProps> = ({ className, hide }) => {
+  const [modalVisibility, showModal, closeModal] = useBooleanState()
+  useTranslation()
+
+  return (
+    <Fragment>
+      <SidebarButton hide={hide} className={className} icon={'share'} onClick={showModal}>
+        <Trans i18nKey={'editor.modal.shareLink.title'} />
+      </SidebarButton>
+      <ShareModal show={modalVisibility} onHide={closeModal} />
+    </Fragment>
+  )
+}