add default dockerfile

Dockerfile

@@ -0,0 +1,8 @@
+FROM adoptopenjdk/openjdk11
+
+ADD ./build/distributions/booru_grabber_bot.tar /
+RUN chown -R 1000:1000 "/booru_grabber_bot"
+
+USER 1000
+
+ENTRYPOINT ["/booru_grabber_bot/bin/booru_grabber_bot", "/booru_grabber_bot/config.json"]