Add workflow to lint README.md.

.github/workflows/markdownlint.yml

@@ -0,0 +1,20 @@
+---
+
+name: tests
+
+on:
+  - push
+  - pull_request
+  - workflow_dispatch
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+      - name: Lint README (markdown)
+        uses: avto-dev/markdown-lint@v1
+        with:
+          config: ./.markdownlint.yml
+          args: ./README.md

.markdownlint.yml

@@ -0,0 +1,11 @@
+---
+
+default: true
+no-hard-tabs:
+  code_blocks: false
+line-length:
+  code_blocks: false
+no-bare-urls: false
+fenced-code-language: false
+no-duplicate-heading:
+  siblings_only: true