Refactored list-feature.js

- Stopped using jQuery
- Moved refactored code to `djangoproject.js`

Not much had to change here because this functionality was already
modernized in 5cad7d2.

Author: adamzap

djangoproject/static/js/djangoproject.js

@@ -34,3 +34,25 @@ document.querySelectorAll('.console-block label').forEach(function (el) {
     });
   });
 });
+
+// Add animation class to feature icons when they are fully visible
+(function () {
+  const observer = new IntersectionObserver(
+    function (entries) {
+      entries.forEach(function (entry) {
+        if (!entry.isIntersecting) {
+          return;
+        }
+
+        entry.target.classList.add('inview');
+
+        observer.unobserve(entry.target);
+      });
+    },
+    { threshold: 1.0 },
+  );
+
+  document.querySelectorAll('.list-features i').forEach(function (el) {
+    observer.observe(el);
+  });
+})();

djangoproject/static/js/main.js

@@ -9,11 +9,6 @@ define(function () {
     return !!document.getElementsByClassName(className).length; //return a boolean
   }
 
-  //feature list
-  if (hasClass('list-features')) {
-    mods.push('mod/list-feature');
-  }
-
   //collapsing list
   if (hasClass('list-collapsing')) {
     mods.push('mod/list-collapsing');