* doc/syntax/modules_and_classes.rdoc:  Added singleton classes
  documentation.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38710 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
fix a typo

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38711 b2dd03c8-39d4-4d8f-98ff-823fe69b080e