ox-taskjuggler: Set the default reports to work out-of-the-box with tj3

ox-taskjuggler: Set the default reports to work out-of-the-box with tj3

* ox-taskjuggler.el (org-taskjuggler-default-reports): Set the default
reports so that the user gets a good out-of-the-box experience with
tj3.

The defaults in the defcustom now out-of-the-box support tj3. If you
really want to export to taskjuggler 2.x the documentation explains
how you can do that.