Update use-transferbench.rst

docs/how to/use-transferbench.rst

 .. meta::
   :description: TransferBench is a utility to benchmark simultaneous transfers between user-specified devices (CPUs or GPUs)
-  :keywords: Using TransferBench, TransferBench Usage, TransferBench How To, TransferBench documentation, TransferBench user guide, TransferBench user manual
+  :keywords: TransferBench usage, TransferBench how to, TransferBench user guide, TransferBench user manual
 
 .. _using-transferbench: