Expose Vim editor extension object for user scripting

assets/js/hooks/cell_editor/live_editor.js

@@ -8,9 +8,12 @@ import RemoteUser from "./live_editor/remote_user";
 import { replacedSuffixLength } from "../../lib/text_utils";
 import { settingsStore } from "../../lib/settings";
 import Doctest from "./live_editor/doctest";
-import { initVimMode } from "monaco-vim";
+import { initVimMode, VimMode } from "monaco-vim";
 import { EmacsExtension, unregisterKey } from "monaco-emacs";
 
+// Expose the Vim extension for customization
+window.unstable_monacoExtensions = { VimMode };
+
 /**
  * Mounts cell source editor with real-time collaboration mechanism.
  */