add velocity

the server now utilizes the velocity proxy for
- domain based connection instead of ports (called forced-hosts in velocity)
- a fancy motd message indicating when only the minecraft server is down, but not the host system

server/velocity.container

@@ -0,0 +1,23 @@
+[Unit]
+Description=Minecraft Proxy Velocity via Podman managed by Systemd
+Documentation=https://docs.papermc.io/velocity/
+
+[Container]
+Image=git.nanody.de/anonoe/jre-alpine:latest
+AutoUpdate=registry
+PublishPort=25565:25565/tcp
+PublishPort=24454:24454/udp
+UserNS=keep-id
+Mount=type=bind,src=PATH/TO/velocity,dst=/mnt/server
+WorkingDir=/mnt/server
+PodmanArgs=--tty --interactive
+Exec=java -Xms500M -Xmx500M -XX:+UseG1GC -XX:G1HeapRegionSize=4M -XX:+UnlockExperimentalVMOptions -XX:+ParallelRefProcEnabled -XX:+AlwaysPreTouch -XX:MaxInlineLevel=15 -jar velocity.jar
+
+[Service]
+SuccessExitStatus=0 143
+TimeoutStartSec=480
+TimeoutStopSec=480
+
+[Install]
+# Start by default on boot
+WantedBy=default.target