updated keywords in readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-quick-booking-manager/trunk@1041976 b8457f37-d9ea-0310-8a92-e5e31aec5664
keyword updated in readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-quick-booking-manager/trunk@1041980 b8457f37-d9ea-0310-8a92-e5e31aec5664