doc: update 'storage' description

doc/man/knot.conf.5in

@@ -764,7 +764,7 @@ A \fI\%reference\fP to a configuration template.
 \fIDefault:\fP not set or \fIdefault\fP (if the template exists)
 .SS storage
 .sp
-A data directory for storing zone files, journal files and timers database.
+A data directory for storing zone files, journal database, and timers database.
 .sp
 \fIDefault:\fP \fB${localstatedir}/lib/knot\fP (configured with \fB\-\-with\-storage=path\fP)
 .SS file

doc/reference.rst

@@ -896,7 +896,7 @@ A :ref:`reference<template_id>` to a configuration template.
 storage
 -------
 
-A data directory for storing zone files, journal files and timers database.
+A data directory for storing zone files, journal database, and timers database.
 
 *Default:* ``${localstatedir}/lib/knot`` (configured with ``--with-storage=path``)