page-footer: mention exit code zero too

Success (zero) is also an "exit code" worth mentioning.

Closes #8833

diff --git a/docs/cmdline-opts/page-footer b/docs/cmdline-opts/page-footer
index 4ba05cfc077195a8ac14b531b05c34a3fa062366..613a3e8de1c6407882b54713982cc1ae10035711 100644 (file)
--- a/docs/cmdline-opts/page-footer
+++ b/docs/cmdline-opts/page-footer
@@ -113,6 +113,8 @@ Makes it the equivalent of --socks5-hostname
 There are a bunch of different error codes and their corresponding error
 messages that may appear under error conditions. At the time of this writing,
 the exit codes are:
+.IP 0
+Success. The operation completed successfully according to the instructions.
 .IP 1
 Unsupported protocol. This build of curl has no support for this protocol.
 .IP 2