chore: upgrade ESLint to v9 and update configurations (#356)

* chore: upgrade ESLint to v9 and update configurations

Upgrade ESLint and configure and update ESLint rules.

* refactor: update code to comply with new ESLint v9 rules

src/components/Search.tsx

@@ -58,7 +58,7 @@ export default function SearchBar({ searchList }: Props) {
   useEffect(() => {
     // Add search result only if
     // input value is more than one character
-    let inputResult = inputVal.length > 1 ? fuse.search(inputVal) : [];
+    const inputResult = inputVal.length > 1 ? fuse.search(inputVal) : [];
     setSearchResults(inputResult);
 
     // Update search string in URL