feat(docs): add docs preview script

Signed-off-by: Swilder-M <poxiaobbs@gmail.com>

docs/preview.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -euo pipefail
+
+PORT="${1:-8080}"
+
+THIS_DIR="$(cd "$(dirname "$(readlink "$0" || echo "$0")")"; pwd -P)"
+
+docker rm doc-preview > /dev/null 2>&1 || true
+docker run -p ${PORT}:8080 -it --name doc-preview \
+    -v "$THIS_DIR"/directory.json:/app/docs/.vuepress/config/directory.json \
+    -v "$THIS_DIR"/en_US:/app/docs/en/latest \
+    -v "$THIS_DIR"/zh_CN:/app/docs/zh/latest \
+    -e DOCS_TYPE=ekuiper \
+    -e VERSION=latest \
+ghcr.io/emqx/emqx-io-docs-frontend:latest