Update list of markdown-compile-* in markdown doc

modules/lang/markdown/README.org

@@ -137,7 +137,8 @@ By default, the value of ~+markdown-compile-functions~ is:
 #+BEGIN_SRC lisp
 '(+markdown-compile-marked
   +markdown-compile-pandoc
-  +markdown-compile-markdown)
+  +markdown-compile-markdown
+  +markdown-compile-multimarkdown)
 #+END_SRC
 
 These functions will attempt to use the marked, pandoc and markdown executables,

modules/lang/markdown/autoload.el

@@ -32,7 +32,7 @@ Runs `+markdown-compile-functions' until the first function to return non-nil,
 otherwise throws an error."
   (or (run-hook-with-args-until-success '+markdown-compile-functions
                                         beg end output-buffer)
-      (user-error "No markdown program could be found. Install marked, pandoc or markdown.")))
+      (user-error "No markdown program could be found. Install marked, pandoc, markdown or multimarkdown.")))
 
 ;;;###autoload
 (defun +markdown-compile-marked (beg end output-buffer)