Fix the missing dash for some options on the help text

[rdwebdesign]

What does this PR aim to accomplish?

Fix the help text.

On the current code, the options -xoff and -yoff were changed to --xoff and --yoff (not sure which commit), so we need to change the help text.
Current help is showing these options with just one dash/hyphen.

How does this PR accomplish the above?

Changing from - to --.
(sometimes I hate this template...)

Link documentation PRs if any are needed to support this PR:

none

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[yubiuser]

It was changed with this commit
b28c112

I changed from single letter flags to whole words to better explain what each flag means. And for more than one letter flag, two dashes seem right