lexical: add RefPlugin to set the ref

src/features/compose/editor/plugins/ref-plugin.tsx

@@ -0,0 +1,18 @@
+import { useLexicalComposerContext } from '@lexical/react/LexicalComposerContext';
+import { LexicalEditor } from 'lexical';
+import React, { useEffect } from 'react';
+
+/** Set the ref to the current Lexical editor instance. */
+const RefPlugin = React.forwardRef<LexicalEditor>((_props, ref) => {
+  const [editor] = useLexicalComposerContext();
+
+  useEffect(() => {
+    if (ref && typeof ref !== 'function') {
+      ref.current = editor;
+    }
+  }, [editor]);
+
+  return null;
+});
+
+export default RefPlugin;