doc: cookbook: Update entry about getting substitutes through Tor.

* doc/guix-cookbook.texi (Getting substitutes from Tor): Update
section warning to mention the use of torsocks when pulling.

doc/guix-cookbook.texi

@@ -15,6 +15,7 @@ Copyright @copyright{} 2020 Oleg Pykhalov@*
 Copyright @copyright{} 2020 Matthew Brooks@*
 Copyright @copyright{} 2020 Marcin Karpezo@*
 Copyright @copyright{} 2020 Brice Waegeneire@*
+Copyright @copyright{} 2020 André Batista@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -1819,10 +1820,16 @@ HTTP/HTTPS will get proxied; FTP, Git protocol, SSH, etc connections
 will still go through the clearnet.  Again, this configuration isn't
 foolproof some of your traffic won't get routed by Tor at all.  Use it
 at your own risk.
+
+Also note that the procedure described here applies only to package
+substitution. When you update your guix distribution with
+@command{guix pull}, you still need to use @command{torsocks} if
+you want to route the connection to guix's git repository servers
+through Tor.
 @end quotation
 
 Guix's substitute server is available as a Onion service, if you want
-to use it to get your substitutes from Tor configure your system as
+to use it to get your substitutes through Tor configure your system as
 follow:
 
 @lisp