* org-agenda.el (org-agenda-start-day): Minor docstring update.

lisp/org-agenda.el

@@ -3412,7 +3412,8 @@ When EMPTY is non-nil, also include days without any entries."
 ;;; Agenda Daily/Weekly
 
 (defvar org-agenda-start-day nil  ; dynamically scoped parameter
-"Custom commands can set this variable in the options section.")
+"Start day for the agenda view.
+Custom commands can set this variable in the options section.")
 (defvar org-starting-day nil) ; local variable in the agenda buffer
 (defvar org-agenda-current-span nil
   "The current span used in the agenda view.") ; local variable in the agenda buffer