Rename azos-core station suite to desktop; move discord out to azos/features

Mirrors the azos-core change: station is renamed desktop (its apps are
generically useful on any machine, work included), discord moves to its
own standalone azos/features/discord (personal-only, so it lives in the
azos project rather than azos-core), and azos-emacs-station becomes
azos-emacs-desktop in lauretta's emacs config to match.

features/lauretta/emacs/config.org

@@ -9,7 +9,7 @@
 (require 'azos-emacs-dev)
 (require 'azos-emacs-editor)
 (require 'azos-emacs-exwm)
-(require 'azos-emacs-station)
+(require 'azos-emacs-desktop)
 #+end_src
 
 * Lauretta specific