Update Dockerfile

Dockerfile

@@ -11,6 +11,9 @@ RUN apt-get update && apt-get install -y \
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
+# Set a writable directory for NLTK data
+ENV NLTK_DATA=/code/nltk_data
+
 # Download punkt data for NLTK
 RUN python -c "import nltk; nltk.download('punkt')"