feat: 🚚 Create readme for each categories and clean repo

Javascript/README.md

@@ -1,3 +1,12 @@
+# Low 
+```javascript
 const phrase = document.getElementById("phrase").value;
 const token = md5(rot13(phrase));
-console.log(token);
+console.log(token);
+```
+
+# Medium
+> In progress
+
+# High
+> In progress