add scripts to build & run with Docker

Or set DOCKER_BIN=podman to use Podman.

scripts/docker-build

@@ -0,0 +1,25 @@
+#!/bin/sh -eu
+
+: "${DOCKER_BIN:=docker}"
+
+cd "$RUN_DIR"
+
+builddir=build
+
+[ -z "${DEBUG:-}" ] || set -x
+
+mkdir -p "$builddir"
+
+poetry export \
+    --with=build \
+    --output="$builddir"/requirements.txt
+
+githash=$(git rev-parse --short HEAD)
+today=$(date -u '+%Y.%m.%d')
+version="${today}+${githash}"
+echo "$version" >"$builddir"/version
+
+$DOCKER_BIN build \
+    --pull \
+    --tag "code.dumpr.org/ducklet/unwind":"$version" \
+    .