Refactor routing in App component to enhance navigation and improve error handling by integrating dynamic routes and updating the NotFound route.

node_modules/micromark-util-decode-numeric-character-reference/index.js

@@ -0,0 +1,32 @@
+/**
+ * Turn the number (in string form as either hexa- or plain decimal) coming from
+ * a numeric character reference into a character.
+ *
+ * Sort of like `String.fromCodePoint(Number.parseInt(value, base))`, but makes
+ * non-characters and control characters safe.
+ *
+ * @param {string} value
+ *   Value to decode.
+ * @param {number} base
+ *   Numeric base.
+ * @returns {string}
+ *   Character.
+ */
+export function decodeNumericCharacterReference(value, base) {
+  const code = Number.parseInt(value, base);
+  if (
+  // C0 except for HT, LF, FF, CR, space.
+  code < 9 || code === 11 || code > 13 && code < 32 ||
+  // Control character (DEL) of C0, and C1 controls.
+  code > 126 && code < 160 ||
+  // Lone high surrogates and low surrogates.
+  code > 55_295 && code < 57_344 ||
+  // Noncharacters.
+  code > 64_975 && code < 65_008 || /* eslint-disable no-bitwise */
+  (code & 65_535) === 65_535 || (code & 65_535) === 65_534 || /* eslint-enable no-bitwise */
+  // Out of range
+  code > 1_114_111) {
+    return "\uFFFD";
+  }
+  return String.fromCodePoint(code);
+}