Add reference to job_submit*.lua scripts

doc/man/man5/slurm.conf.5

@@ -698,8 +698,8 @@ These are intended to be site\-specific plugins which can be used to set
 default job parameters and/or logging events.
 Sample plugins available in the distribution include "cnode", "defaults",
 "logging", "lua", and "partition".
-See the SLURM code in "src/plugins/job_submit" and modify the code to satisfy
-your needs.
+For examples of use, see the SLURM code in "src/plugins/job_submit" and
+"contribs/lua/job_submit*.lua" then modify the code to satisfy your needs.
 No job submission plugins are used by default.
 
 .TP