fix the displaying of any non-string values of variables included in …

…the prompt

Previously, non-string (e.g. numerical) values were breaking the variable values preview feature.

prompterator/main.py

@@ -500,7 +500,7 @@ def set_up_prompt_attrs_area(st_container):
         # create text of used prompt's variables and their values
         vars_values = ""
         for var in vars:
-            vars_values += var + ":\n    " + st.session_state.row.get(var, "none") + "\n"
+            vars_values += var + ":\n    " + str(st.session_state.row.get(var, "none")) + "\n"
 
         st_container.text_area(
             label=f"Attributes used in a prompt",