chore: update help text copy on dataset settings (apache#30775)

Co-authored-by: Michael S. Molina <[email protected]>
Co-authored-by: Joe Li <[email protected]>

superset-frontend/src/components/Datasource/DatasourceEditor.jsx

@@ -895,7 +895,8 @@ class DatasourceEditor extends PureComponent {
           fieldKey="default_endpoint"
           label={t('Default URL')}
           description={t(
-            'Default URL to redirect to when accessing from the dataset list page',
+            `Default URL to redirect to when accessing from the dataset list page.
+            Accepts relative URLs such as <span style=„white-space: nowrap;”>/superset/dashboard/{id}/</span>`,
           )}
           control={<TextControl controlId="default_endpoint" />}
         />