syntax fix

Author: Nyholm

cache.rst

@@ -137,16 +137,18 @@ will create pool with service id of ``cache.[type]``
                 https://symfony.com/schema/dic/services/services-1.0.xsd">
 
             <framework:config>
+                <!--
+                default_doctrine_provider: Service: cache.doctrine
+                default_psr6_provider: Service: cache.psr6
+                default_redis_provider: Service: cache.redis
+                default_memcached_provider: Service: cache.memcached
+                default_pdo_provider: Service: cache.pdo
+                -->
                 <framework:cache directory="%kernel.cache_dir%/pools"
-                    <!-- Service: cache.doctrine -->
                     default_doctrine_provider="app.doctrine_cache"
-                    <!-- Service: cache.psr6 -->
                     default_psr6_provider="app.my_psr6_service"
-                    <!-- Service: cache.redis -->
                     default_redis_provider="redis://localhost"
-                    <!-- Service: cache.memcached -->
                     default_memcached_provider="memcached://localhost"
-                    <!-- Service: cache.pdo -->
                     default_pdo_provider="doctrine.dbal.default_connection"
                 />
             </framework:config>