Rework descriptions for mailing list, options, job files

Rework descriptions for mailing list, options, job files

In general, make the existing document less ambiguous:

o Use consistent formatting/layout when describing options
o always refer to options with "--" prefix.
o reduce use of pronouns: "its" and "this" are often ambigous.
o remove use of "you" to describe user actions/choices
o add reference to examples/ directory

Signed-off-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>