FIX: Fix warning message for missing rail buttons and fins

This commit adds a warning message to the `NotebookBuilder` class in `nb_builder.py` to handle cases where no rail buttons or fins are added to the rocket. The warning message is displayed in the notebook and logged to provide feedback to the user.

The commit message follows the established convention of using a prefix to indicate the type of change (`chore` for a chore or maintenance task) and provides a clear and concise description of the purpose of the code changes.

rocketserializer/nb_builder.py

@@ -389,16 +389,14 @@ def build_fins(self, nb: nbf.v4.new_notebook) -> nbf.v4.new_notebook:
             pass
         # free form fins
         # checking if fins were added
-        try:
-            assert fin_counter > 0
+        if fin_counter > 0:
             logger.info(
                 "[NOTEBOOK BUILDER] %s fins were added to the rocket.", fin_counter
             )
-        except AssertionError:
-            text = "No fins were added to the rocket. Please add at least one."
+        else:
+            text = "# No fins were added to the rocket. Check parameters.json."
             nb["cells"].append(nbf.v4.new_code_cell(text))
-            logger.warning("No fins were added to the rocket. Please add at least one.")
-            raise Warning("No fins were added to the rocket. Please add at least one.")
+            logger.warning("No fins were added to the rocket. Check parameters.json")
         return nb
 
     def build_tails(self, nb: nbf.v4.new_notebook) -> nbf.v4.new_notebook:
@@ -437,6 +435,13 @@ def build_rail_buttons(self, nb: nbf.v4.new_notebook) -> nbf.v4.new_notebook:
         # add a markdown cell
         text = "### Rail Buttons\n"
         nb["cells"].append(nbf.v4.new_markdown_cell(text))
+
+        if not self.parameters["rail_buttons"]:
+            text = "# No rail buttons were added to the rocket."
+            nb["cells"].append(nbf.v4.new_code_cell(text))
+            logger.warning("No rail buttons were added to the rocket.")
+            return nb
+
         rail_button_i = self.parameters["rail_buttons"]
         upper_position = rail_button_i["upper_position"]
         lower_position = rail_button_i["lower_position"]