feat: update docker and pipeline

- Add workflow to publish to GHCR
- Add workflow to build Docker image
- Add zap2xmlrc config example
- Update Dockerfile to run continuously

entrypoint.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+while :
+do
+	DATE=$(date)
+	/opt/zap2xml.pl "$OPT_ARGS"
+	echo "Last run time: $DATE"
+	echo "Will run in $SLEEPTIME seconds"
+	sleep "$SLEEPTIME"
+done