Update main.js

Author: underscoreBon

javascript/main.js

@@ -0,0 +1,14 @@
+var coll = document.getElementsByClassName("collapsible");
+    var i;
+    
+    for (i = 0; i < coll.length; i++) {
+      coll[i].addEventListener("click", function() {
+        this.classList.toggle("active");
+        var content = this.nextElementSibling;
+        if (content.style.display === "block") {
+          content.style.display = "none";
+        } else {
+          content.style.display = "block";
+        }
+      });
+    }