Add Docker support with Dockerfile and docker-compose.yml

- Introduced a Dockerfile for building the application using a multi-stage build process.
- Added docker-compose.yml to define services for the application and PostgreSQL database.
- Updated README.md with instructions for running the application using Docker and Docker Compose.

Dockerfile

@@ -0,0 +1,33 @@
+FROM rust:1.76-slim-bullseye as builder
+
+WORKDIR /usr/src/app
+COPY . .
+
+# Build the application
+RUN cargo build --release
+
+# Create a new stage with a minimal image
+FROM debian:bullseye-slim
+
+WORKDIR /usr/local/bin
+
+# Install necessary runtime dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy the built binary from the builder stage
+COPY --from=builder /usr/src/app/target/release/hospitalapi .
+
+# Create a directory for the .env file
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+# Copy the .env file
+COPY .env .
+
+# Expose the port the app runs on
+EXPOSE 3000
+
+# Run the application
+CMD ["./hospitalapi"]