.zshrc: Don't exit shell on ^D

This is super annoying when you're in a pager like more or less and
you are pressing ^D to go down. When you reach the end of the input
then you send ^D to the shell and it exits!

Signed-off-by: Alan Orth <alan.orth@gmail.com>

.zshrc

@@ -7,6 +7,7 @@ unsetopt hist_ignore_space      # ignore space prefixed commands
 setopt hist_reduce_blanks       # trim blanks
 setopt inc_append_history       # add commands as they are typed, don't wait until shell exit
 setopt share_history            # share hist between sessions
+setopt ignoreeof                # don't exit the shell on ^D (EOF)
 
 # emacs bindings
 bindkey -e