added docker and modify the file so it work

Dockerfile

@@ -0,0 +1,20 @@
+FROM python:3.11-slim
+
+# Set the working directory
+WORKDIR /app
+
+# Copy the requirements file and install dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy the rest of the application code
+COPY . .
+
+# Ensure the database directory exists for SQLite persistence
+RUN mkdir -p /app/db
+
+# Expose the application port
+EXPOSE 8000
+
+# Command to start the application
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]