Fix Space YAML metadata

README.md

@@ -8,7 +8,7 @@ sdk_version: "6.1.0"
 python_version: "3.10"
 app_file: app.py
 pinned: false
-short_description: RAG Question Answering demo with BM25 + Dense retrieval and optional reranker.
+short_description: RAG QA demo BM25 + Dense + reranker
 ---
 
 # RAG QA (BM25 + Dense + OpenAI-compatible providers)