Remove package description info from manual page

This table isn't necessary because it's part of the DESCRIPTION file
and included other places. It's also out of sync with the actual
information, and I always forget to update it.

man/xts-package.Rd

@@ -9,13 +9,6 @@ Extensible time series class and methods, extending and behaving
 like zoo.
 }
 \details{
-\tabular{ll}{
-Package: \tab xts\cr
-Type: \tab Package\cr
-Version: \tab 0.10-2\cr
-Date: \tab 2018-03-13\cr
-License: \tab GPL (>= 2)\cr
-}
 Easily convert one of \R's many time-series (and non-time-series)
 classes to a true time-based object which inherits all of zoo's
 methods, while allowing for new time-based tools where appropriate.