add hw2

node_modules/dayjs/esm/plugin/dayOfYear/index.js

@@ -0,0 +1,9 @@
+export default (function (o, c, d) {
+  var proto = c.prototype;
+
+  proto.dayOfYear = function (input) {
+    // d(this) is for badMutable
+    var dayOfYear = Math.round((d(this).startOf('day') - d(this).startOf('year')) / 864e5) + 1;
+    return input == null ? dayOfYear : this.add(input - dayOfYear, 'day');
+  };
+});