Map keyboard shortcuts on windows (#526)

* Map keyboard shortcuts on windows

* Fixed also saving commands

* Fix keyboard shortcut for keyboard shortcuts

* Fixed guide

* Cmd -> Mod

app/components/Editor/utils.js

@@ -0,0 +1,11 @@
+// @flow
+
+/**
+ * Detect Cmd or Ctrl by platform for keyboard shortcuts
+ */
+export function isModKey(event: SyntheticKeyboardEvent) {
+  const isMac =
+    typeof window !== 'undefined' &&
+    /Mac|iPod|iPhone|iPad/.test(window.navigator.platform);
+  return isMac ? event.metaKey : event.ctrlKey;
+}