Store cache lifetime in config

app/config/config.yml

@@ -49,6 +49,7 @@ wallabag_core:
     language: en
     rss_limit: 50
     reading_speed: 1
+    cache_lifetime: 10
 
 wallabag_import:
     allow_mimetypes: ['application/octet-stream', 'application/json', 'text/plain']

app/config/config_dev.yml

@@ -40,3 +40,11 @@ swiftmailer:
     transport: smtp
     host: 'localhost'
     port: 1025
+
+# If you want to use cache for queries used in WallabagExtension
+# Uncomment the following lines
+#doctrine:
+#    orm:
+#        metadata_cache_driver: apcu
+#        result_cache_driver: apcu
+#        query_cache_driver: apcu