Implement builder image

Add docker build to create a shared image for running CI pipelines and
docker builds based on debian.

tag-release.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+# Finds the next available r<year>.<week>.<bump> identifier for the current year and week
+YEAR_WEEK=$(date -u +%g.%-V)
+YEAR=${YEAR_WEEK:0:2}
+WEEK=${YEAR_WEEK:3}
+LAST_BUMP=$(git tag --list | grep '^r'$YEAR'\.'$WEEK'\.\(0\|[1-9][0-9]*\)$' | cut -d . -f 3 | sort -nr | head -n 1)
+RELEASE=r${YEAR_WEEK}.$(( ${LAST_BUMP:--1} + 1 ))
+
+git tag $RELEASE
+echo Tagged $RELEASE