feat(mostUsedChar): adicionando resolucao desafio 9

mostRepeatedChar

09-mostRepeatedChar/index.js

@@ -1,4 +1,15 @@
 export function mostUsedChar(text) {
     // implementar logica aqui
-    return ""
+    const value = text.toLocaleLowerCase().split("").sort();
+
+    let counts = {};
+    value.forEach(function (x) {
+        counts[x] = (counts[x] || 0) + 1;
+    });
+
+    const maior = Object.keys(counts).sort(function (a, b) {
+        return counts[a] > counts[b] ? -1 : counts[b] > counts[a] ? 1 : 0;
+    })[0];
+
+    return maior;
 }