fix example

docs/components/dropdown.md

@@ -311,6 +311,7 @@ Dropdown panels will be clipped if they're inside a container that has `overflow
 
 <style>
   .dropdown-hoist {
+    position: relative;
     border: solid 2px var(--sl-panel-border-color);
     padding: var(--sl-spacing-medium);
     overflow: hidden;