docs(codes): Add (key) codes documentation

Create codes documentation for standardized keys.

Closes #218.  Fixes #308.  Ref #21.

docs/src/components/codes/ToastyContainer.jsx

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2020 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: CC-BY-NC-SA-4.0
+ */
+
+import React from "react";
+import { ToastContainer } from "react-toastify";
+import "react-toastify/dist/ReactToastify.css";
+
+export default function ToastyContainer() {
+  return (
+    <ToastContainer
+      position="bottom-right"
+      autoClose={2000}
+      hideProgressBar={true}
+      newestOnTop={true}
+    />
+  );
+}
+
+ToastyContainer.propTypes = {};