task with short docs

functions2.ex

defmodule Mix.Tasks.MyTasks.Functions do
   use Mix.Task
   @shortdoc "Returns functions in Module"
   @moduledoc ~S"""
   This is used to list out the all available functions in the module.           
   You suppose to pass module_name as parameter to the task.

   #Usage
   ```
      mix my_tasks.functins Hello

   ```
   This list out all the functins in the module Hello
   """
   def run([module_name]) do 
     module = Module.concat Elixir,module_name
     data = apply(module, :__info__, [:functions])
     IO.inspect data
   end
end