[docs] move site gen to a post-push hook

.githooks/post-push

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+set -Eeuo pipefail
+
+REMOTE_NAME="${1:-}"
+REMOTE_URL="${2:-}"
+
+if [[ "${MEANAS_DOCS_PUBLISHING:-0}" == "1" ]]; then
+    exit 0
+fi
+
+if [[ "$REMOTE_NAME" != "origin" ]]; then
+    exit 0
+fi
+
+publish_docs=0
+while read -r local_ref local_sha remote_ref remote_sha; do
+    if [[ "$local_ref" == "refs/heads/master" && "$remote_ref" == "refs/heads/master" && "$local_sha" != "0000000000000000000000000000000000000000" ]]; then
+        publish_docs=1
+        break
+    fi
+done
+
+if [[ "$publish_docs" != "1" ]]; then
+    exit 0
+fi
+
+ROOT="$(git rev-parse --show-toplevel)"
+cd "$ROOT"
+
+if ! command -v mkdocs >/dev/null 2>&1; then
+    echo "[meanas docs hook] mkdocs not found; skipping docs publish" >&2
+    exit 0
+fi
+
+DOCS_SITE_URL="${DOCS_SITE_URL:-$(git config --get meanas.docsSiteUrl || true)}"
+export DOCS_SITE_URL
+
+echo "[meanas docs hook] building docs after push to ${REMOTE_NAME} (${REMOTE_URL})" >&2
+MEANAS_DOCS_PUBLISHING=1 ./make_docs.sh
+echo "[meanas docs hook] publishing docs-site branch" >&2
+MEANAS_DOCS_PUBLISHING=1 ./scripts/publish_docs_branch.sh site docs-site