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/micromark-util-encode/index.js

@@ -0,0 +1,33 @@
+const characterReferences = {'"': 'quot', '&': 'amp', '<': 'lt', '>': 'gt'}
+
+/**
+ * Encode only the dangerous HTML characters.
+ *
+ * This ensures that certain characters which have special meaning in HTML are
+ * dealt with.
+ * Technically, we can skip `>` and `"` in many cases, but CM includes them.
+ *
+ * @param {string} value
+ *   Value to encode.
+ * @returns {string}
+ *   Encoded value.
+ */
+export function encode(value) {
+  return value.replace(/["&<>]/g, replace)
+
+  /**
+   * @param {string} value
+   *   Value to replace.
+   * @returns {string}
+   *   Encoded value.
+   */
+  function replace(value) {
+    return (
+      '&' +
+      characterReferences[
+        /** @type {keyof typeof characterReferences} */ (value)
+      ] +
+      ';'
+    )
+  }
+}