feat(org-mode): disable section body indentation

Due to wrapping text at 80 characters, having section content indented
to match the heading level of the section caused annoyance whenever I
restructured documents, as often the line wrapping was no longer correct
and needed adjustment.

modules/org-mode/siren-org-mode.el

@@ -39,6 +39,8 @@
   (org-return-follows-link t)
   (org-special-ctrl-a/e t)
   (org-special-ctrl-k t)
+  (org-adapt-indentation nil)
+  (org-hide-leading-stars nil)
 
   (org-directory (if (file-directory-p "~/Dropbox/org")
                      "~/Dropbox/org" "~/org"))