Refactor file_name variable in app.py

The commit changes the value of the file_name variable from "mpt-7b-instruct-q5_1-ggjt.bin" to "mpt-7b-storywriter-q5_1.bin".

app.py

@@ -2,7 +2,7 @@ import gradio as gr
 from llm_rs import AutoModel,SessionConfig,GenerationConfig,Precision
 
 repo_name = "rustformers/mpt-7b-ggml"
-file_name = "mpt-7b-instruct-q5_1-ggjt.bin"
+file_name = "mpt-7b-storywriter-q5_1.bin"
 
 examples = [
     "Write a travel blog about a 3-day trip to Thailand.",