Add NEWS for Ruby 2.6.0

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61487 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -0,0 +1,13 @@
+# -*- rdoc -*-
+
+= NEWS for Ruby 2.6.0
+
+This document is a list of user visible feature changes made between
+releases except for bug fixes.
+
+Note that each entry is kept so brief that no reason behind or
+reference information is supplied with.  For a full list of changes
+with all sufficient information, see the ChangeLog file or Redmine
+(e.g. <tt>https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER</tt>)
+
+== Changes since the 2.5.0 release