feat: import html-to-react from https://github.com/hedgedoc/html-to-react

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

html-to-react/src/NodeToReactElementTransformer.ts

@@ -0,0 +1,15 @@
+/*
+ * SPDX-FileCopyrightText: 2020 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { Node } from 'domhandler'
+import { ReactElement } from 'react'
+
+export interface NodeToReactElementTransformer {
+  (
+    node: Node,
+    index: number | string,
+    transform?: NodeToReactElementTransformer
+  ): ReactElement | void | null | string
+}