Add changes I've made manually on the build server

This also adds the xmr-stak cypto miner container image I created
That one is the first of potentially many images I won't push to the official Docker Hub registries, but insted to my own private registry

xmr-stak/Dockerfile

@@ -0,0 +1,5 @@
+FROM alpine:latest
+RUN apk add python3
+COPY ./ /opt
+WORKDIR /opt
+CMD ./miner.py -m1