add .dockerignore, add Dockerfile, add default.nix, udpate README.md, move packages into respective category(dev/production)

Dockerfile

@@ -0,0 +1,10 @@
+FROM node:lts-alpine3.12
+RUN mkdir /data
+COPY ./ /data
+WORKDIR /data
+RUN ls -lash
+RUN yarn install --production
+RUN adduser --disabled-password --gecos "" slowdowner
+RUN chown slowdowner:slowdowner /data
+CMD yarn run start
+EXPOSE 8080