Fix typo

Author: javiereguiluz

frontend/asset_mapper.rst

@@ -753,7 +753,7 @@ else to configure in your server.
 
 .. tip::
 
-    AssetMapper provides a ``assets:compress`` CLI command and a service called
+    AssetMapper provides an ``assets:compress`` CLI command and a service called
     ``asset_mapper.compressor`` that you can use anywhere in your application to
     compress any kind of files (e.g. files uploaded by users to your application).