UPDATE: Adds web app (#79)

Things missing:

* Browse mode
* Front end tests
* Storybook

webapp/src/components/tests/util.test.ts

@@ -0,0 +1,7 @@
+import { expect, test } from "vitest";
+import { isNavigationKey } from "../util";
+
+test("checks arrow left is a navigation key", () => {
+  expect(isNavigationKey("ArrowLeft")).toBe(true);
+  expect(isNavigationKey("Arrow")).toBe(false);
+});