config.json in trackler-2.0.8.39

- old
+ new

@@ -100,9 +100,18 @@
       "difficulty": 1,
       "topics": [
       ]
     },
     {
+      "slug": "rotational-cipher",
+      "difficulty": 1,
+      "topics": [
+         "strings",
+         "logic",
+         "control-flow (loops)"
+      ]
+    },
+    {
       "slug": "difference-of-squares",
       "difficulty": 1,
       "topics": [
       ]
     },