Bind: S-SPC to scroll up

Or in Emacs terms, scroll (contents) down.

README.org

@@ -118,8 +118,9 @@ These bindings are common to all of the following buffer types:
 
 +  Move between events: ~TAB~ / ~<backtab>~
 +  Scroll down (at the end of a room buffer, mark it as read and bury it): ~SPC~
++  Scroll up: ~S-SPC~
 +  Move to the fully-read marker: ~M-SPC~
-+  Load older messages: at top of buffer, ~M-v~ or ~mwheel-scroll~
++  Load older messages: at top of buffer, scroll up (i.e. ~S-SPC~, ~M-v~ or ~mwheel-scroll~)
 +  Show source of event at point: ~v~
 +  Show another room: ~r~
 +  Show room list buffer: ~R~

ement-room.el

@@ -85,6 +85,7 @@ Used to, e.g. call `ement-room-compose-org'.")
     (define-key map (kbd "v") #'ement-room-view-event)
     (define-key map (kbd "RET") #'ement-room-send-message)
     (define-key map (kbd "SPC") #'ement-room-scroll-up-mark-read)
+    (define-key map (kbd "S-SPC") #'ement-room-scroll-down-command)
     (define-key map (kbd "M-SPC") #'ement-room-go-to-read-marker)
     (define-key map (kbd "S-<return>") #'ement-room-send-reply)
     (define-key map (kbd "<backtab>") #'ement-room-goto-prev)