problems(js): add “2648. Generate Fibonacci Sequence”

Signed-off-by: Matej Focko <mfocko@redhat.com>

problems/js/generate-fibonacci-sequence.js

@@ -0,0 +1,17 @@
+/**
+ * @return {Generator<number>}
+ */
+var fibGenerator = function*() {
+    let a = 0, b = 1;
+
+    while (true) {
+        yield a;
+        [a, b] = [b, a + b];
+    }
+};
+
+/**
+ * const gen = fibGenerator();
+ * gen.next().value; // 0
+ * gen.next().value; // 1
+ */