Small typo fixes in yaf docs

Suggested by Colin Scroggins <colinscroggins@gmail.com>

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@331201 c90b9560-bf6c-de11-be94-00142212c4b1
Adding information that resource is not a valid type hint.  It isn't mentioned at all.

-- 
Provided by Steve Tauber (steve@onzra.com)

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@331202 c90b9560-bf6c-de11-be94-00142212c4b1