Add note about serving public as web root

Laravel 3 docs had a little more specificity regarding the fact that only the public folder should be web accessible.  This change adds back this recommendation.  Inspired by this forum post: [http://forums.laravel.io/viewtopic.php?id=6751]
Removed mention of bundles
Merge pull request #183 from memco/patch-3

Add note about serving public as web root