updated job throttling documentation to illustrate defautl categories associated for auxillary jobs.
updated job throttling documentation to illustrate defautl categories
associated for auxillary jobs.

pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus