add example to AS::Gzip

activesupport/lib/active_support/gzip.rb

@@ -2,7 +2,14 @@
 require 'stringio'
 
 module ActiveSupport
-  # A convenient wrapper for the zlib standard library that allows compression/decompression of strings with gzip.
+  # A convenient wrapper for the zlib standard library that allows
+  # compression/decompression of strings with gzip.
+  #
+  #   gzip = ActiveSupport::Gzip.compress('compress me!')
+  #   # => "\x1F\x8B\b\x00o\x8D\xCDO\x00\x03K\xCE\xCF-(J-.V\xC8MU\x04\x00R>n\x83\f\x00\x00\x00"
+  #
+  #   ActiveSupport::Gzip.decompress(gzip)
+  #   # => "compress me!" 
   module Gzip
     class Stream < StringIO
       def initialize(*)