Add .devcontainer folder

.devcontainer/Dockerfile

@@ -0,0 +1,9 @@
+FROM simon987/sist2-build
+
+RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash
+RUN apt update -y; apt install -y nodejs && rm -rf /var/lib/apt/lists/*
+
+ENV DEBIAN_FRONTEND=noninteractive
+ENV LANG C.UTF-8
+ENV LC_ALL C.UTF-8
+