Note brokenness of compression helper

doc/compress.html

@@ -15,6 +15,8 @@
    helper */
 </pre>
 
+    <h2>!! The compression helper is currently broken. I hope to have it working again in a few days. !!</h2>
+
     <p>To optimize loading CodeMirror, especially when including a
     bunch of different modes, it is recommended that you combine and
     minify (and preferably also gzip) the scripts. This page makes
@@ -148,4 +150,4 @@
     </script>
 
   </body>
-</html>
\ No newline at end of file
+</html>