[examples/replace] Minor fixes to comments and add SYNOPSIS.

examples/rename.lua

@@ -2,6 +2,9 @@
 -- Basic mass file renamer using osx and
 -- standard Lua gsub().
 --
+-- SYNOPSIS:
+-- rename.lua <pattern> <replacement> [directory]
+--
 -- Renames every file inside a directory (defaults to current directory).
 -- Trimmed down but functional and useful variant of util-linux rename(1).
 --
@@ -9,7 +12,7 @@
 -- lua rename.lua 'something' 'something_else'
 -- lua rename.lua '(%w+).lua' '%1.lua.bk' src
 --
--- Author Lorenzo Cogotti, The DoubleFourteen Code Forge
+-- Author: Lorenzo Cogotti, The DoubleFourteen Code Forge
 
 local io = require 'io'
 local osx = require 'osx'