Add api_key for loading private model

In case a user wants the simple Space but accessing a private Model

template/app_simple.py

@@ -1,5 +1,8 @@
+import os
 import gradio as gr
 
+API_KEY=os.environ.get('HUGGING_FACE_HUB_TOKEN', None)
+
 article = """---
 This space was created using [SD Space Creator](https://huggingface.co/spaces/anzorq/sd-space-creator)."""
 
@@ -8,4 +11,5 @@ gr.Interface.load(
     title="""$title""",
     description="""$description""",
     article=article,
+    api_key=API_KEY,
     ).queue(concurrency_count=20).launch()