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/mdast-util-to-markdown/lib/handle/break.js

@@ -0,0 +1,30 @@
+/**
+ * @import {Break, Parents} from 'mdast'
+ * @import {Info, State} from 'mdast-util-to-markdown'
+ */
+
+import {patternInScope} from '../util/pattern-in-scope.js'
+
+/**
+ * @param {Break} _
+ * @param {Parents | undefined} _1
+ * @param {State} state
+ * @param {Info} info
+ * @returns {string}
+ */
+export function hardBreak(_, _1, state, info) {
+  let index = -1
+
+  while (++index < state.unsafe.length) {
+    // If we can’t put eols in this construct (setext headings, tables), use a
+    // space instead.
+    if (
+      state.unsafe[index].character === '\n' &&
+      patternInScope(state.stack, state.unsafe[index])
+    ) {
+      return /[ \t]/.test(info.before) ? '' : ' '
+    }
+  }
+
+  return '\\\n'
+}