* .document: [DOC] add rbconfig. [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56160 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2016-09-14 12:52:00 +00:00 · 2016-09-14 12:52:00 +00:00 · 2bbd6f18cd
--- a/.document
+++ b/.document
@ -9,6 +9,8 @@
 # prelude
 prelude.rb

+rbconfig.rb
+
 # the lib/ directory (which has its own .document file)
 lib