feat: add weakset content (#1869)

* feat: add Set JavaScript content

* feat: add weakset javascript content

* Update content/roadmaps/106-javascript/content/104-javascript-data-structures/101-keyed-collections/103-weak-set.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/106-javascript/content/104-javascript-data-structures/101-keyed-collections/103-weak-set.md

@@ -1 +1,8 @@
-# Weak set
+# WeakSet
+
+`WeakSet` objects are collections of objects. Just as with `Sets`, each object in a `WeakSet` may occur only once; all objects in a `WeakSet`'s collection are unique.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet'>WeakSet</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://javascript.info/weakmap-weakset'>WeakMap and WeakSet</BadgeLink>