add Makefile Dockerfile README.md

Dockerfile

@@ -0,0 +1,16 @@
+
+# Dockerfile
+# Base build environment for hdwalletpy: Python 3.11 + build tools + venv support
+FROM python:3.11-slim
+
+# Install build tools, headers, and venv module
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    python3-dev \
+    libffi-dev \
+    python3-venv \
+ && rm -rf /var/lib/apt/lists/*
+
+# Set working directory for bind mounts
+WORKDIR /app
+