Add SymLinksIfOwnerMatch to .htaccess to squelch Apache RewriteEngine error

Apache would show the following error

> [Thu Jul 11 15:15:14 2013] [error] [client ::1] Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden: /Users/llunesu/Sites/

SymLinksIfOwnerMatch seems to be the safer of the two, so I added that to .htaccess

Also added a note about .htaccess to the README.md