ci: add markdownlint for the docs

.github/workflows/mkdocs.yaml

@@ -25,9 +25,16 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
+      - name: markdownlint
+        uses: nosborn/[email protected]
+        with:
+          files: docs
+          config_file: .markdownlint.yml
       - uses: actions/setup-python@v5
         with:
           python-version: 3.x
+          cache: pip
+          cache-dependency-path: requirements-docs.txt
       - run: pip install -r requirements-docs.txt
       - run: mkdocs build
       - uses: actions/upload-pages-artifact@v2

.markdownlint.yml

@@ -0,0 +1,37 @@
+---
+# Enable default rules
+default: true
+
+# MD007 - Unordered list indentation
+# Sets nested list indents to 4 spaces instead of the default of 2.
+# Required by Python-Markdown used by mkdocs
+MD007:
+    indent: 4
+
+# MD010 - No hard tabs
+# No hard tabs allowed in docs. Use 4 spaces instead.
+# This is disabled inline when used.
+MD010: true
+
+# MD013 - Line length
+# Defaults to 80 characters.
+MD013: false
+
+# MD014 - Dollar signs used before commands without showing output
+# Ignores terminal examples using dollar signs without any output examples after.
+# These occur in multiple places throughout our docs.
+MD014: false
+
+# MD024 - Multiple headings with the same content
+# Multiple identical headings in the document are not allowed
+# This is disabled on all of the release notes pages in docs/release-notes
+MD024: true
+
+# MD033 - Inline HTML
+# Triggered when raw HTML is used in a markdown document
+# Disabled inline when used.
+MD033: true
+
+# MD041 - First line in a file should be a top-level heading
+# This requires a top-level heading as the first line in every doc.
+MD041: true