added markdownlint run script

.github/workflows/markdownlint.yml

@@ -23,4 +23,4 @@ jobs:
         run: sudo npm install -g markdownlint-cli
 
       - name: validate all markdown files
-        run: cd "${{ github.workspace }}" && markdownlint -p .gitignore .
+        run: cd "${{ github.workspace }}" && ./tests/run-markdownlint.sh

README.md

@@ -206,6 +206,7 @@ Standard MIT License, see LICENSE file for full text
 * in file `./openwrt/Makefile`: change `PKG_VERSION:=X.Y.Z` and maybe `PKG_RELEASE:=1`
 * copy file `./luamqtt-scm-1.rockspec` to `./rockspecs/luamqtt-X.Y.Z-1.rockspec` change `local package_version = "scm"`, `local package_version = "X.Y.Z"`
 * run `./tests/run-luacheck.sh` and check output for errors
+* run `./tests/run-markdownlint.sh` and check output for errors
 * run `./tests/run-for-all-lua-versions.sh` and check output for errors
 * run `./openwrt/make-package-without-openwrt-sources.sh` and check output for errors
 * run `git commit`, `git tag vX.Y.Z`

tests/run-markdownlint.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# please install node.js runtime for your OS ( https://nodejs.org/ )
+# then run `npm install -g markdownlint-cli` (maybe with sudo)
+
+npx markdownlint-cli -p .gitignore .