Make some tweaks to Org mode stuff

Namely, open ~/exo/index.org on start-up, and get rid of the message in
the *Scratch* buffer.

config.org

@@ -225,36 +225,47 @@ needs to be set up to install them if they aren't already.
       (require 'org-tempo))
   #+end_src
 
-  Org is better suited as scratch space than Emacs lisp, I'd say.
+  Org is better suited as scratch space than Funamental, I'd say.
 
   #+begin_src emacs-lisp
     (setq initial-major-mode 'org-mode)
+    (setq initial-scratch-message "")
   #+end_src
 
-  Set up a keybinding for =org-agenda= and tell it where to look. I
-  have a bunch of org documents making up a sort of wiki which I keep
-  under =~/exo=.
+  I always want [[file:~/exo/index.org][~/exo/index.org]] to open on start-up, as that's where I
+  keep links to whatever I happen to be doing at any given time; one
+  does that by setting [[help:initial-buffer-choice][initial-buffer-choice]]
 
   #+begin_src emacs-lisp
-    (define-key global-map (kbd "C-c a") 'org-agenda)
-    (setq org-agenda-files
-          (directory-files-recursively "~/exo" "\.org$"))
+    (setq initial-buffer-choice "~/exo/index.org")
   #+end_src
 
-  Log when tasks were marked =DONE=, just for graphs.
+** Agenda
 
-  #+begin_src emacs-lisp
-    (setq org-log-done t)
-  #+end_src
+   Set up a keybinding for [[help:org-agenda][org-agenda]] and tell it where to look. I
+   have a bunch of org documents making up a sort of wiki which I keep
+   under [[file:~/exo][~/exo]].
 
-  I often want to see TODO items that aren't scheduled to decide on
-  something to do (if I've already done all the scheduled things), so
-  it's nice for =org-agenda= to have an option for that.
+   #+begin_src emacs-lisp
+     (define-key global-map (kbd "C-c a") 'org-agenda)
+     (setq org-agenda-files
+           (directory-files-recursively "~/exo" "\.org$"))
+   #+end_src
 
-  #+begin_src emacs-lisp
-    (setq org-agenda-custom-commands
-          '(("u" "Unscheduled tasks" tags "-SCHEDULED={.+}/!+TODO")))
-  #+end_src
+   Log when tasks were marked =DONE=, just for graphs.
+
+   #+begin_src emacs-lisp
+     (setq org-log-done t)
+   #+end_src
+
+   I often want to see TODO items that aren't scheduled to decide on
+   something to do (if I've already done all the scheduled things), so
+   it's nice for [[help:org-agenda][org-agenda]] to have an option for that.
+
+   #+begin_src emacs-lisp
+     (setq org-agenda-custom-commands
+           '(("u" "Unscheduled tasks" tags "-SCHEDULED={.+}/!+TODO")))
+   #+end_src
 
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