Fix settingeditor-extension README link

packages/settingeditor-extension/README.md

@@ -1,3 +1,3 @@
 # @jupyterlab/settingeditor-extension
 
-An extension for JupyterLab which provides a user-editable interface for the JupyterLab [settings registry](../coreutils/src/settingregistry.ts).
+An extension for JupyterLab which provides a user-editable interface for the JupyterLab [settings registry](../settingregistry/src/settingregistry.ts).