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-core-commonmark/lib/character-reference.js

@@ -0,0 +1,149 @@
+/**
+ * @import {
+ *   Code,
+ *   Construct,
+ *   State,
+ *   TokenizeContext,
+ *   Tokenizer
+ * } from 'micromark-util-types'
+ */
+
+import { decodeNamedCharacterReference } from 'decode-named-character-reference';
+import { asciiAlphanumeric, asciiDigit, asciiHexDigit } from 'micromark-util-character';
+/** @type {Construct} */
+export const characterReference = {
+  name: 'characterReference',
+  tokenize: tokenizeCharacterReference
+};
+
+/**
+ * @this {TokenizeContext}
+ *   Context.
+ * @type {Tokenizer}
+ */
+function tokenizeCharacterReference(effects, ok, nok) {
+  const self = this;
+  let size = 0;
+  /** @type {number} */
+  let max;
+  /** @type {(code: Code) => boolean} */
+  let test;
+  return start;
+
+  /**
+   * Start of character reference.
+   *
+   * ```markdown
+   * > | a&b
+   *      ^
+   * > | a{b
+   *      ^
+   * > | a	b
+   *      ^
+   * ```
+   *
+   * @type {State}
+   */
+  function start(code) {
+    effects.enter("characterReference");
+    effects.enter("characterReferenceMarker");
+    effects.consume(code);
+    effects.exit("characterReferenceMarker");
+    return open;
+  }
+
+  /**
+   * After `&`, at `#` for numeric references or alphanumeric for named
+   * references.
+   *
+   * ```markdown
+   * > | a&b
+   *       ^
+   * > | a{b
+   *       ^
+   * > | a	b
+   *       ^
+   * ```
+   *
+   * @type {State}
+   */
+  function open(code) {
+    if (code === 35) {
+      effects.enter("characterReferenceMarkerNumeric");
+      effects.consume(code);
+      effects.exit("characterReferenceMarkerNumeric");
+      return numeric;
+    }
+    effects.enter("characterReferenceValue");
+    max = 31;
+    test = asciiAlphanumeric;
+    return value(code);
+  }
+
+  /**
+   * After `#`, at `x` for hexadecimals or digit for decimals.
+   *
+   * ```markdown
+   * > | a{b
+   *        ^
+   * > | a	b
+   *        ^
+   * ```
+   *
+   * @type {State}
+   */
+  function numeric(code) {
+    if (code === 88 || code === 120) {
+      effects.enter("characterReferenceMarkerHexadecimal");
+      effects.consume(code);
+      effects.exit("characterReferenceMarkerHexadecimal");
+      effects.enter("characterReferenceValue");
+      max = 6;
+      test = asciiHexDigit;
+      return value;
+    }
+    effects.enter("characterReferenceValue");
+    max = 7;
+    test = asciiDigit;
+    return value(code);
+  }
+
+  /**
+   * After markers (`&#x`, `&#`, or `&`), in value, before `;`.
+   *
+   * The character reference kind defines what and how many characters are
+   * allowed.
+   *
+   * ```markdown
+   * > | a&b
+   *       ^^^
+   * > | a{b
+   *        ^^^
+   * > | a	b
+   *         ^
+   * ```
+   *
+   * @type {State}
+   */
+  function value(code) {
+    if (code === 59 && size) {
+      const token = effects.exit("characterReferenceValue");
+      if (test === asciiAlphanumeric && !decodeNamedCharacterReference(self.sliceSerialize(token))) {
+        return nok(code);
+      }
+
+      // To do: `markdown-rs` uses a different name:
+      // `CharacterReferenceMarkerSemi`.
+      effects.enter("characterReferenceMarker");
+      effects.consume(code);
+      effects.exit("characterReferenceMarker");
+      effects.exit("characterReference");
+      return ok;
+    }
+    if (test(code) && size++ < max) {
+      effects.consume(code);
+      return value;
+    }
+    return nok(code);
+  }
+}