DOC Document changes to the updateRelativeLink

en/04_Changelogs/5.0.0.md

@@ -482,6 +482,7 @@ This is a major release and contains many breaking API changes. Deprecation warn
   - Previous extension hook implementations of `SecurityAdmin::updateEditForm($form)` still works as the extension hook is called in [`ModelAdmin::getEditForm()`](api:SilverStripe\Admin\ModelAdmin::getEditForm()).
   - The *Users*, *Groups* and *Roles* tabs no longer share the `/admin/security` path and instead have their own dedicated paths. e.g. `/admin/security/users`
 - `isDev` and `isTest` query string arguments have been removed due to security concerns (see [ss-2018-005](https://www.silverstripe.org/download/security-releases/ss-2018-005/)).
+- The `updateRelativeLink()` extension hook for updating the result of [SiteTree::RelativeLink()](api:SilverStripe\CMS\Model\SiteTree::RelativeLink()) has changed signature, allowing you to update the resultant link itself instead of just the component parts. If you are using this extension hook you will need to update the method signature and logic to match. See [SiteTreeExtension::updateRelativeLink()](api:SilverStripe\CMS\Model\SiteTreeExtension::updateRelativeLink()) for more details.
 - The default value for the `RESOURCES_DIR` const has been changed to to "_resources"
   - The [`Library::DEFAULT_RESOURCES_DIR`](api:SilverStripe\VendorPlugin\Library::DEFAULT_RESOURCES_DIR) constant in `silverstripe/vendor-plugin` has been changed to match.
   - This can still be customised using `extra.resources-dir` in your `composer.json` file ([see relevant docs](/developer_guides/templates/requirements/#configuring-your-project-exposed-folders)).