[Docs] Include hidden files in artifact upload

Add include-hidden-files: true to upload-artifact action to ensure
.nojekyll and .well-known directory are included in the build artifact.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: peterschmidt85

.github/workflows/build-docs.yml

@@ -23,3 +23,4 @@ jobs:
           name: site
           path: site
           retention-days: 1
+          include-hidden-files: true