fix lint rules and small readme improve

Day01/js/solution.js

@@ -15,12 +15,10 @@ function extractDigits(line) {
     let digitsFound = [];
     let i = 0;
     while (i < line.length) {
-        let matched = false;
         for (const [word, digit] of Object.entries(digitMap)) {
             if (line.startsWith(word, i)) {
                 digitsFound.push(digit);
-                i += word.length - 1; // Advance the index
-                matched = true;
+                i += word.length - 1;
                 break;
             }
         }