feat(docker): Test script using docker

- README updated with docker instructions

Dockerfile

@@ -0,0 +1,23 @@
+# Use Debian Slim as base image
+FROM debian:stable-slim
+
+# Install necessary dependencies
+RUN apt-get update && apt-get install -y \
+    sudo \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set working directory
+WORKDIR /script
+
+# Copy the initialization script
+COPY init-linux-harden.sh /script/
+
+# Make the script executable
+RUN chmod +x /script/init-linux-harden.sh
+
+# Set entrypoint to run the script
+ENTRYPOINT ["/bin/sh", "-c"]
+
+# Default command to run the script
+CMD ["/script/init-linux-harden.sh"]