add warning about vimium breaking cloud9 keyboard shortcuts

package.json

@@ -80,7 +80,7 @@
         "c9.automate": "#47e2c429c9",
         "c9.ide.ace.emmet": "#6dc4585e02",
         "c9.ide.ace.gotoline": "#d33220b1e0",
-        "c9.ide.ace.keymaps": "#334a65192f",
+        "c9.ide.ace.keymaps": "#15e7d23a2a",
         "c9.ide.ace.repl": "#4b88a85b7b",
         "c9.ide.ace.split": "#0ae0151c78",
         "c9.ide.ace.statusbar": "#3aab0b67e0",