Add pa11y-ci for accessibility testing.

Add pa11y-ci-reporter-html and also upload the HTML results to CI if there are failures

.github/workflows/docs.yml

@@ -39,3 +39,17 @@ jobs:
 
       - name: Test docs
         run: npm run docs
+
+      - name: Run accessibility tests
+        run: npm run docs-accessibility
+
+      - name: Generate HTML accessibility results
+        run: npm run docs-pa11y-html
+        if: failure()
+
+      - name: Upload accessibility results
+        uses: actions/upload-artifact@v2
+        if: failure()
+        with:
+          name: pa11y-ci-results
+          path: .pa11y/

.gitignore

@@ -50,3 +50,5 @@ Thumbs.db
 # Folders to ignore
 /js/coverage/
 /node_modules/
+/.pa11y/
+/pa11y-ci-results.json

build/.pa11yci.json

@@ -0,0 +1,11 @@
+{
+  "standard": "WCAG2AA",
+  "level": "error",
+  "concurrency": 4,
+  "runners": [
+    "htmlcs"
+  ],
+  "defaults": {
+    "hideElements": ".bd-search, [class*=-success], [class*=-info], [class*=-light]"
+  }
+}