* doc/extension.rdoc, doc/extension.ja.rdoc: add editor local
variables, with commenting out by :enddoc: directives which are
just ignored unless code object mode. [Bug #12111]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53948 b2dd03c8-39d4-4d8f-98ff-823fe69b080e