Add documentatio to the mixin

lib/msf/core/exploit/cmdstager_echo.rb

@@ -4,15 +4,23 @@ require 'msf/core/exploit/cmdstager'
 
 module Msf
 
-###
+####
+# Allows for staging cmd to arbitrary payloads through the CmdStagerEcho.
 #
-# This mixin provides an interface for staging cmd to arbitrary payloads
-#
-###
+# This stager uses the echo's "-e" flag, that enable interpretation of
+# backslash escapes, to drop an ELF with the payload embedded to disk.
+# The "-e" flag is usually available on linux environments. This stager
+# has been found useful on restricted linux based embedded devices.
+####
+
 module Exploit::CmdStagerEcho
 
   include Msf::Exploit::CmdStager
 
+  # Initializes a CmdStagerEcho instance for the supplied payload
+  #
+  # @param exe [String] The payload embedded into an ELF
+  # @return [Rex::Exploitation::CmdStagerEcho] Stager instance
   def create_stager(exe)
     Rex::Exploitation::CmdStagerEcho.new(exe)
   end