A convenience script for previewing docs changes. (#20569)

Author: benjyw

build-support/preview_docs.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# Expects a sibling dir called "pantsbuild.org" containing a clean clone
+# of the https://github.com/pantsbuild/pantsbuild.org repo.
+
+DIFF_FILE=$(mktemp)
+
+git diff main docs/ > "${DIFF_FILE}"
+
+cd ../pantsbuild.org
+
+git diff --stat --exit-code > /dev/null || (echo "Expected clean git state in the pantsbuild/pantsbuild.org repo" && exit 1)
+
+git checkout main
+
+git apply --allow-empty "${DIFF_FILE}"
+
+rm -f "${DIFF_FILE}"
+
+npm start