README.EXT.ja: add redirect [ruby-core:68631]

see r50090 for detail

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50124 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Mon Mar 30 22:02:55 2015  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* README.EXT.ja: add redirect [ruby-core:68631]
+
 Mon Mar 30 14:42:41 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* win32/win32.c (fileattr_to_unixmode, winnt_lstat): deal with

README.EXT.ja

@@ -0,0 +1 @@
+doc/extension.ja.rdocに移動しました