Make planetiler-openmaptiles runnable as a standalone project (#19)

scripts/check-doc-links.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o pipefail
+set -o nounset
+
+find . -name '*.md' -not -path '*/target/*' -print0 | xargs -I {} -n 1 -0 markdown-link-check --quiet --config .github/workflows/docs_mlc_config.json {}