add line break

Author: guimachiavelli

learn/indexing/rename_an_index.md

@@ -27,4 +27,4 @@ curl \
   --data-binary '{ "uid": "INDEX_B" }'
 ```
 
-Replace `INDEX_A` with the current name of your index, and `INDEX_B` with its new name.
+Replace `INDEX_A` with the current name of your index, and `INDEX_B` with its new name.