Fixed coast -Td, -Tm via explain_-T_rose

[tparker37]

Fixed [coast -Td, -Tm] from explain_-T_rose: Don't repeat the option, just say
Completed during AGU2019 workshop

Fixes #2227

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[PaulWessel]

Great, but please change the first Draws to Draw, if you can.

[seisman]

Suggested change

	Draws a map directional rose on the map at the location defined by
	Draw a map directional rose on the map at the location defined by

[PaulWessel]

I dont have permission to commit those suggestions, apparently.

[seisman]

Me too. We have to wait for @tparker37 to respond, or we can open a separate PR.