update documentation index.md (zh_cn)

update it refer to the latest en version.
Merge pull request #256 from SteveVallay/new

update documentation index.md (zh_cn)
Link to zh version of wikipedia article (zh_cn)
Remove explanation of 'koan' (zh_cn)
added service issue of ruby-lang.org
Merge branch '20130706-status-issue'
tiny
fix plural form
Some fixes in service issue news post (en)
Separate paragraph for 'impact' in news post (en)
Fix 'translator' field in news post
update issue's status
added current issue infomation
Fixes in news post update (en, ja)
added md5 miss-match issues
Translate service issue of ruby-lang.org (pl)
update current status: ftp.ruby-lang.org resumed
style
Updated service issue of ruby-lang.org (pl)
Sync about and community page content (pl)