Update asset_pipeline.textile

修正pipeline单词
Merge pull request #78 from allenfantasy/master

申请翻译Active Record：数据表关联
Merge pull request #77 from fxhover/master

Update asset_pipeline.textile
Update active_record_querying.textile
Update contributing_to_ruby_on_rails.textile
Update contributing_to_ruby_on_rails.textile
Update documents_CN.yaml