Integrate markdownlint

.github/workflows/markdownlint.yml

@@ -0,0 +1,69 @@
+name: markdownlint
+
+env:
+  NODE_VERSION: 18
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - "**/*.md"
+      - ".markdownlint.json"
+      - ".markdownlintignore"
+      - "package.json"
+      - "yarn.lock"
+  pull_request:
+    branches:
+      - master
+    paths:
+      - "**/*.md"
+      - ".markdownlint.json"
+      - ".markdownlintignore"
+      - "package.json"
+      - "yarn.lock"
+
+jobs:
+  lint:
+    name: Run markdownlint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out to repository
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+
+      # If the linter found any errors, it will exit with a non-zero code,
+      # which will cause the job to fail
+      - name: Run markdownlint
+        run: yarn markdownlint .
+
+  notify:
+    name: Send Slack notification on failure
+    runs-on: ubuntu-latest
+    # We should wait for the lint job to finish before handling the notification
+    needs: lint
+    # With always() we can run this job even if the previous job failed, but we also
+    # should check if the event is push or the PR is coming from the same repository
+    if: ${{ always() && (github.event_name == 'push' || github.event.pull_request.head.repo.full_name == github.repository) }}
+    steps:
+      # Get the workflow conclusion
+      - uses: technote-space/workflow-conclusion-action@v3
+
+      # Send a Slack notification if the conclusion is failure
+      - uses: 8398a7/action-slack@v3
+        with:
+          status: failure
+          fields: workflow, repo, message, commit, author, eventName, ref, job
+          job_name: Run markdownlint
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: ${{ env.WORKFLOW_CONCLUSION == 'failure' }}

.markdownlint.json

@@ -0,0 +1,17 @@
+{
+  "ul-indent": { "indent": 4 },
+  "line-length": {
+    "stern": true,
+    "line_length": 120
+  },
+  "no-multiple-blanks": { "maximum": 2 },
+  "no-inline-html": {
+    "allowed_elements": ["a", "details", "summary", "img", "pre"]
+  },
+  "no-duplicate-header": { "siblings_only": true },
+  "no-blanks-blockquote": false,
+  "no-bare-urls": false,
+  "ul-style": { "style": "dash" },
+  "blanks-around-fences": { "list_items": false },
+  "emphasis-style": { "style": "asterisk" }
+}

.markdownlintignore

@@ -0,0 +1 @@
+node_modules/

.vscode/extensions.json

@@ -1,5 +1,6 @@
 {
     "recommendations": [
-        "adguard.adblock"
+        "adguard.adblock",
+        "davidanson.vscode-markdownlint"
     ]
 }

package.json

@@ -16,11 +16,14 @@
         "prepare": "node .husky/install.mjs"
     },
     "lint-staged": {
-        "*.txt": "aglint"
+        "*.txt": "aglint",
+        "*.md": "markdownlint"
     },
     "devDependencies": {
         "@adguard/aglint": "^2.0.8",
         "husky": "^9.0.7",
-        "lint-staged": "^15.2.1"
+        "lint-staged": "^15.2.1",
+        "markdownlint": "^0.33.0",
+        "markdownlint-cli": "^0.39.0"
     }
 }