pySim-shell: Improve documentation

A number of new commands were recently introduced without proper
coverage in the documentation (user manual).  This includes equip,
bulk_script and others.

Change-Id: Ide7ba68ad90f6e5c2a41a2e3de22534258ebb7fd
diff --git a/pySim-shell.py b/pySim-shell.py
index 1fc09ef..3fc5859 100755
--- a/pySim-shell.py
+++ b/pySim-shell.py
@@ -380,6 +380,7 @@
 	@cmd2.with_argparser(echo_parser)
 	@cmd2.with_category(CUSTOM_CATEGORY)
 	def do_echo(self, opts):
+		"""Echo (print) a string on the console"""
 		self.poutput(opts.string)
 
 @with_default_category('pySim Commands')