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/is-plain-obj/readme.md

@@ -0,0 +1,58 @@
+# is-plain-obj
+
+> Check if a value is a plain object
+
+An object is plain if it's created by either `{}`, `new Object()`, or `Object.create(null)`.
+
+## Install
+
+```
+$ npm install is-plain-obj
+```
+
+## Usage
+
+```js
+import isPlainObject from 'is-plain-obj';
+import {runInNewContext} from 'node:vm';
+
+isPlainObject({foo: 'bar'});
+//=> true
+
+isPlainObject(new Object());
+//=> true
+
+isPlainObject(Object.create(null));
+//=> true
+
+// This works across realms
+isPlainObject(runInNewContext('({})'));
+//=> true
+
+isPlainObject([1, 2, 3]);
+//=> false
+
+class Unicorn {}
+isPlainObject(new Unicorn());
+//=> false
+
+isPlainObject(Math);
+//=> false
+```
+
+## Related
+
+- [is-obj](https://github.com/sindresorhus/is-obj) - Check if a value is an object
+- [is](https://github.com/sindresorhus/is) - Type check values
+
+---
+
+<div align="center">
+	<b>
+		<a href="https://tidelift.com/subscription/pkg/npm-is-plain-obj?utm_source=npm-is-plain-obj&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
+	</b>
+	<br>
+	<sub>
+		Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
+	</sub>
+</div>