Add Dockerfile and README

Dockerfile

+FROM node:current-bullseye AS assets
+
+ADD . /src
+WORKDIR /src
+RUN npm install && ./node_modules/.bin/webpack
+
+FROM registry.git.autistici.org/ai3/docker/static-content:master
+COPY --from=assets /src/assets/ /var/www/

README.md

+Simple admin dashboard for A/I.
+
+Contains links to useful internal systems and account management tools.