Add Dockerfile for development environment setup with Python, Git, and Poetry

.devcontainer/Dockerfile

@@ -0,0 +1,5 @@
+FROM python:3.14-slim
+# Instalar git y herramientas básicas
+RUN apt-get update && apt-get install -y git curl && rm -rf /var/lib/apt/lists/*
+# Instalar Poetry
+RUN pip install poetry