irssi/config: add /spam alias — cat file from ~/ascii to channel

/spam <name> runs 'cat ~/ascii/<name>' via EXEC -out, which sends
each line of output as a message to the current channel/query. Good
for posting ASCII art.

Usage: /spam <filename>  (file lives at ~/ascii/<filename>)

.irssi/config

@@ -158,6 +158,7 @@ aliases = {
   SB = "SCROLLBACK";
   SBAR = "STATUSBAR";
   SIGNOFF = "QUIT";
+  SPAM = "EXEC -out cat ~/ascii/$0";
   SV = "MSG * Irssi $J ($V) - http://www.irssi.org";
   T = "TOPIC";
   UB = "UNBAN";