feat(mostUsedChar): fazendo funcão

09-mostRepeatedChar/index.js

@@ -1,4 +1,10 @@
 export function mostUsedChar(text) {
-    // implementar logica aqui
-    return ""
-}
+  // implementar logica aqui
+  let textLower = text.toLowerCase().split("").sort();
+  for (let index = 1; index < textLower.length; index++) {
+    textLower = textLower.filter((e, i, a) => a.indexOf(e) !== i);
+  }
+
+  let letter = [...new Set(textLower)];
+  return letter.join("");
+}