Add a Dockerfile for dev environments other than codespaces

.devcontainer/Dockerfile

@@ -0,0 +1,11 @@
+# Not actually used by the devcontainer, but it is used by gitpod
+ARG VARIANT=17-bullseye
+FROM mcr.microsoft.com/vscode/devcontainers/java:0-${VARIANT}
+ARG NODE_VERSION="none"
+RUN if [ "${NODE_VERSION}" != "none" ]; then su vscode -c "umask 0002 && . /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1"; fi
+ARG USER=vscode
+VOLUME /home/$USER/.m2
+VOLUME /home/$USER/.gradle
+ARG JAVA_VERSION=17.0.7-ms
+RUN sudo mkdir /home/$USER/.m2 /home/$USER/.gradle && sudo chown $USER:$USER /home/$USER/.m2 /home/$USER/.gradle
+RUN bash -lc '. /usr/local/sdkman/bin/sdkman-init.sh && sdk install java $JAVA_VERSION && sdk use java $JAVA_VERSION'