added an entry (date/format.rb).

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2471 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/README

@@ -8,6 +8,7 @@ cgi.rb		CGI support library
 cgi/session	CGI session class
 complex.rb	complex number suppor
 date.rb		date object
+date/format.rb	date parsing and formatting
 date2.rb	date object (obsolete; use date)
 debug.rb	ruby debugger
 delegate.rb	delegates messages to other object