uniform hyphen usage addresses #772

[professorjamesmoriarty]

I opt'd to use a single hyphen for options. And made a small note in regards to the ability to swap. I think a single hyphen fits because of the internal help examples use a single hyphen.

[odeke-em]

Thanks for working on this @shaggytwodope.

I have some comments on this:

1. Please update the commit message to:

README: consistent hyphen usage for options in examples

Fixes #772

2. I prefer using -- for long options because -- is customary for CLI's and the GNU long options style is very widespread for folks using the command line. In the future.
   I'll probably get rid of Go's flag in favour of something that accepts long and short options GNU style because Go's flag package also has some problems like the options have to precede any arguments so

$ drive list fewHere --long

would not catch --long, and would treat it as a path instead of an option. For it to work it would have to be:

$ drive list --long fewHere

yet in all other CLIs that I've encountered, the ordering won't matter.

[professorjamesmoriarty]

@odeke-em Commit message changed. And yeah I think the "long" options make much more sense. For now tho I think this solves some confusion in the short term.

[odeke-em]

Fair enough, I see your concern with confusion results because firstly help gives - for help.

Thank you for fixing and advocating this.
LGTM!