feat(test): #16 add test_nested_func

tests/test_nested_func.py

@@ -0,0 +1,11 @@
+def hello_world(s: str) -> str:
+    ans = ""
+
+    def nested_func(s: str) -> str:
+        if s == "complexipy":
+            return "complexipy is awesome!"
+        return f"I don't know what to say, hello {s}(?)"
+
+    ans = nested_func(s)
+
+    return ans