Add multiarch Docker support and GHCR publishing

- Implement multiarch Dockerfile supporting linux/amd64 and linux/arm64
- Optimize Dockerfile with better layer caching and reduced image size
- Update CI/CD pipeline to use Docker Buildx for multiarch builds
- Add GitHub Container Registry (GHCR) as second publishing target
- Configure automatic tagging (latest, branch name, commit SHA)
- Add QEMU emulation support for cross-platform builds
- Enable GitHub Actions layer caching for faster builds
- Completely revamp README with comprehensive documentation
- Add professional badges (build status, Docker Hub, GHCR, license, Python)
- Include detailed setup instructions for Docker Hub and GHCR
- Add Docker Compose example and configuration table
- Document multiarch build process and state persistence

Dockerfile

@@ -4,14 +4,15 @@ FROM alpine:3.18
 # Set the working directory inside the container
 WORKDIR /app
 
-# Copy the entire current directory into the container at /app
+# Install Python dependencies in a single layer
+RUN apk add --no-cache python3 py3-pip
+
+# Copy requirements first for better layer caching
+COPY requirements.txt /app/
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy the application code
 COPY . /app
 
-# Install any Python dependencies
-
-RUN apk add python3
-RUN apk add py3-pip
-RUN pip install -r requirements.txt
-
 # Run Python script
 CMD ["python", "main.py"]