Update docs/manual/en-US/chapters/packages/data.md
Merge pull request #1788 from elinw/patch-13

Fix typos
Add missing argument to JAccess::checkGroup in rules.php
Add JFeed chapter to manual
Merge pull request #1792 from elinw/rules

Add missing argument to JAccess::checkGroup in rules.php
Merge pull request #1806 from elinw/feeds

Add JFeed chapter to manual
Merge pull request #10 from joomla/staging

Staging