ox-org: Fix typo in docstring

* lisp/ox-org.el (org-org-export-to-org):
(org-org-publish-to-org): Use "Org" instead of "org".

lisp/ox-org.el

@@ -274,7 +274,7 @@ non-nil."
 ;;;###autoload
 (defun org-org-export-to-org
   (&optional async subtreep visible-only body-only ext-plist)
-  "Export current buffer to an org file.
+  "Export current buffer to an Org file.
 
 If narrowing is active in the current buffer, only export its
 narrowed part.
@@ -307,7 +307,7 @@ Return output file name."
 
 ;;;###autoload
 (defun org-org-publish-to-org (plist filename pub-dir)
-  "Publish an org file to org.
+  "Publish an Org file to Org.
 
 FILENAME is the filename of the Org file to be published.  PLIST
 is the property list for the given project.  PUB-DIR is the