fix: Correct GitHub username in blog authors.yml

Fix broken GitHub profile and image links caused by invalid username with dot.

Changes:
- Replace YAML key "pepe.amengual" with "jamengual" (GitHub usernames cannot contain dots)
- Update profile URL: https://github.com/pepe.amengual → https://github.com/jamengual
- Update image URL: https://github.com/pepe.amengual.png → https://github.com/jamengual.png
- Update author reference in Azure authentication blog post

This fixes:
- Broken GitHub profile links in blog posts
- Missing/broken author avatar images
- Docusaurus author metadata resolution

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: jamengual

website/blog/2025-11-07-azure-authentication-support.mdx

@@ -2,7 +2,7 @@
 title: Native Azure Authentication Support
 description: Authenticate to Azure using Atmos with device code flow, OIDC, and service principals - works identically to az login
 slug: azure-authentication-support
-authors: [pepe.amengual]
+authors: [jamengual]
 tags:
   - feature
   - azure

website/blog/authors.yml

@@ -10,7 +10,7 @@ osterman:
   url: https://github.com/osterman
   image_url: https://github.com/osterman.png
 
-pepe.amengual:
+jamengual:
   name: Pepe Amengual
-  url: https://github.com/pepe.amengual
-  image_url: https://github.com/pepe.amengual.png
+  url: https://github.com/jamengual
+  image_url: https://github.com/jamengual.png