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/nostr-tools/lib/esm/nip39.js

@@ -0,0 +1,21 @@
+// nip39.ts
+var _fetch;
+try {
+  _fetch = fetch;
+} catch {
+}
+function useFetchImplementation(fetchImplementation) {
+  _fetch = fetchImplementation;
+}
+async function validateGithub(pubkey, username, proof) {
+  try {
+    let res = await (await _fetch(`https://gist.github.com/${username}/${proof}/raw`)).text();
+    return res === `Verifying that I control the following Nostr public key: ${pubkey}`;
+  } catch (_) {
+    return false;
+  }
+}
+export {
+  useFetchImplementation,
+  validateGithub
+};