add-show-menu-items in drscheme:unit:frame

This method is called during the construction of the view menu. This method is intended to be overridden. It is expected to add other Show/Hide menu items to the show menu.

See also get-show-menu.

• (send a-drscheme:unit:frame add-show-menu-items show-menu) -> void
     show-menu : (is-a?/c menu%)

  Adds the ``Show Definitions'', ``Show Interactions'' and ``Show Contour'' menu items.