STORM-3089: Describe worker hooks in documentation
STORM-3089: Describe worker hooks in documentation

hmcl/storm-apache,kishorvpatil/incubator-storm,erikdw/storm,kishorvpatil/incubator-storm,erikdw/storm,erikdw/storm,hmcl/storm-apache,kishorvpatil/incubator-storm,kishorvpatil/incubator-storm,erikdw/storm,hmcl/storm-apache,kishorvpatil/incubator-storm,erikdw/storm,hmcl/storm-apache,erikdw/storm,hmcl/storm-apache,hmcl/storm-apache,erikdw/storm,kishorvpatil/incubator-storm,kishorvpatil/incubator-storm,hmcl/storm-apache