Create directory structure for frontend with requisite justfile changes. (#6)

Reviewed-on: #6
Co-authored-by: Drew Galbraith <drew@tiramisu.one>
Co-committed-by: Drew Galbraith <drew@tiramisu.one>

frontend/react-router.config.ts

@@ -0,0 +1,7 @@
+import type { Config } from "@react-router/dev/config";
+
+export default {
+  // Config options...
+  // Server-side render by default, to enable SPA mode set this to `false`
+  ssr: true,
+} satisfies Config;