Removed whitespaces | added parameters description from Graceful Controller

[delihus]

Just filled descriptions of the controller parameters from a Graceful Controller.

[SteveMacenski]

Want to add those into Nav2 / docs.nav2.org for the controller as well? :-)

[delipl]

As I see it is already filled https://github.com/ros-navigation/docs.nav2.org/blob/master/configuration/packages/configuring-docking-server.rst

I can change docs to the same description as in the gracefull controller

[SteveMacenski]

Great! I didn't realize I updated the docs.nav2.org yet. I think the readme in navigation2 (https://github.com/ros-navigation/navigation2/tree/main/nav2_docking#configuration) also is missing these descriptions. Making them all the same would be fantastic - thank you! :-)