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

node_modules/ccount/index.d.ts

@@ -0,0 +1,11 @@
+/**
+ * Count how often a character (or substring) is used in a string.
+ *
+ * @param {string} value
+ *   Value to search in.
+ * @param {string} character
+ *   Character (or substring) to look for.
+ * @return {number}
+ *   Number of times `character` occurred in `value`.
+ */
+export function ccount(value: string, character: string): number