ox-html: Fix docstrings

* lisp/ox-html.el (org-html-postamble-format,
  org-html-preamble-format): Fix docstrings.

lisp/ox-html.el

@@ -1025,7 +1025,7 @@ precedence over this variable."
   "Alist of languages and format strings for the HTML postamble.
 
 The first element of each list is the language code, as used for
-the LANGUAGE keyword.  See `org-export-default-language'
+the LANGUAGE keyword.  See `org-export-default-language'.
 
 The second element of each list is a format string to format the
 postamble itself.  This format string can contain these elements:
@@ -1034,10 +1034,9 @@ postamble itself.  This format string can contain these elements:
   %a stands for the author's name.
   %e stands for the author's email.
   %d stands for the date.
-  %c will be replaced by creator information.  See
-   `org-html-creator-string'.
+  %c will be replaced by `org-html-creator-string'.
   %v will be replaced by `org-html-validation-link'.
-  %T will be replaced by the creation time of the HTML file.
+  %T will be replaced by the export time.
 
 If you need to use a \"%\" character, you need to escape it
 like that: \"%%\"."
@@ -1086,7 +1085,7 @@ precedence over this variable."
   "Alist of languages and format strings for the HTML preamble.
 
 The first element of each list is the language code, as used for
-the #+LANGUAGE keyword.
+the LANGUAGE keyword.  See `org-export-default-language'.
 
 The second element of each list is a format string to format the
 preamble itself.  This format string can contain these elements:
@@ -1095,9 +1094,9 @@ preamble itself.  This format string can contain these elements:
   %a stands for the author's name.
   %e stands for the author's email.
   %d stands for the date.
-  %c will be replaced by information about Org/Emacs versions.
+  %c will be replaced by `org-html-creator-string'.
   %v will be replaced by `org-html-validation-link'.
-  %T will be replace by the creation time of the file.
+  %T will be replaced by the export time.
 
 If you need to use a \"%\" character, you need to escape it
 like that: \"%%\".