nvmecontrol: Flesh out nvmecontrol format information

[imp]

Summary

The format command takes a number of different parameters. Include a
brief summary of what the values mean, though since the driver's support
for metadata is at best weak, 0's are almost always used for values
other than -f format. Add example.

Sponsored by: Netflix

[chuck]

This looks good and helps explain (with examples) a common NVMe stumbling block.

sbin/nvmecontrol/nvmecontrol.8

451

I wonder if "index as reported ..." instead of "#, " would make it clear to the user they are using indices reported by the drive and not the format size.

[pauamma_chezdork.com]

English and markup LGTM.

[imp]

update per Chuck's idea of making it clear it's an index. Hopefully this makes
it clearer. Thanks Chuck!

[chuck]

LGTM