bug#4963: Please copy Phil Sung's installation instructions into www.gnu.org/s/emacs/#Obtaining

[Noam Postavsky]

Closing since the info at http://web.psung.name/emacs/setup.html is
now obsolete.

The website has been updated recently, there are installation
instructions at https://www.gnu.org/software/emacs/download.html. In
discussions about it, Richard Stallman was against adding more distro
specific detail to the install instructions, some opposition to that
view[1], but in the end it seems to have stayed non-distro specific.

[1]: https://lists.gnu.org/archive/html/emacs-devel/2016-02/msg01220.html