Install Salt plugin for Hammer via foreman-installer

Refs PR 1013 in foreman-installer

Author: maximiliankolb

guides/common/modules/proc_installing-the-salt-plugin.adoc

@@ -19,6 +19,7 @@ endif::[]
 [options="nowrap" subs="attributes"]
 ----
 # {foreman-installer} \
+--enable-foreman-cli-salt \
 --enable-foreman-plugin-salt \
 --enable-foreman-proxy-plugin-salt
 ----