feat: initialize markr nostr bookmark client

- Add project structure with TypeScript, React, and Vite
- Implement nostr authentication using browser extension (NIP-07)
- Add NIP-51 compliant bookmark fetching and display
- Create minimal UI with login and bookmark components
- Integrate applesauce-core and applesauce-react libraries
- Add responsive styling with dark/light mode support
- Include comprehensive README with setup instructions

This is a minimal MVP for a nostr bookmark client that allows users to
view their bookmarks according to NIP-51 specification.

node_modules/applesauce-react/dist/hooks/use-observable-memo.js

@@ -0,0 +1,9 @@
+import { useObservableEagerState, useObservableState } from "observable-hooks";
+import { useMemo } from "react";
+import { of } from "rxjs";
+export function useObservableMemo(factory, deps) {
+    return useObservableState(useMemo(() => factory() || of(undefined), deps));
+}
+export function useObservableEagerMemo(factory, deps) {
+    return useObservableEagerState(useMemo(() => factory() || of(undefined), deps));
+}