Add documentation for the storeutl app

Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3542)

doc/man1/storeutl.pod

+=pod
+
+=head1 NAME
+
+storeutl - STORE utility
+
+=head1 SYNOPSIS
+
+B<openssl> B<storeutl>
+[B<-help>]
+[B<-out file>]
+[B<-noout>]
+[B<-passin arg>]
+[B<-text arg>]
+[B<-engine id>]
+B<uri> ...
+
+=head1 DESCRIPTION
+
+The B<storeutl> command can be used to display the contents (after decryption
+as the case may be) fetched from the given URIs.
+
+=head1 COMMAND OPTIONS
+
+=over 4
+
+=item B<-help>
+
+Print out a usage message.
+
+=item B<-out filename>
+
+specifies the output filename to write to or standard output by
+default.
+
+=item B<-noout>
+
+this option prevents output of the PEM data.
+
+=item B<-passin arg>
+
+the key password source. For more information about the format of B<arg>
+see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
+
+=item B<-text>
+
+Prints out the objects in text form, similarly to the B<-text> output from
+B<openssl x509>, B<openssl pkey>, etc.
+
+=item B<-engine id>
+
+specifying an engine (by its unique B<id> string) will cause B<storeutl>
+to attempt to obtain a functional reference to the specified engine,
+thus initialising it if needed.
+The engine will then be set as the default for all available algorithms.
+
+=back
+
+=head1 SEE ALSO
+
+L<openssl(1)>
+
+=head1 HISTORY
+
+B<openssl> B<storeutl> was added to OpenSSL 1.1.1.
+
+=head1 COPYRIGHT
+
+Copyright 2016-2017 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut