feat: add CMS Accessibility Specialist agent

Added a vibe description for CMS Developer role.## What does this PR do?

Adds a new CMS Accessibility Specialist agent to the Engineering Division, specializing in WCAG 2.1 AA compliance, remediation, and accessible development for WordPress and Drupal websites.

## Agent Information (if adding/modifying an agent)

- **Agent Name**: CMS Accessibility Specialist
- **Category**: Engineering
- **Specialty**: WCAG 2.1 AA auditing, accessible Gutenberg blocks and Drupal components, video captions, audio transcripts, SVG accessibility, motion/animation controls, screen reader testing (NVDA, JAWS, VoiceOver, TalkBack), and editorial accessibility training

## Checklist

- [x] Follows the agent template structure from CONTRIBUTING.md
- [x] Includes YAML frontmatter with `name`, `description`, `color`
- [x] Has concrete code/template examples (for new agents)
- [x] Tested in real scenarios
- [x] Proofread and formatted correctly

Author: itlasso

engineering/engineering-cms-developer.md

@@ -3,6 +3,7 @@ name: CMS Developer
 emoji: 🧱
 description: Drupal and WordPress specialist for theme development, custom plugins/modules, content architecture, and code-first CMS implementation
 color: blue
+vibe: Makes sure every user — regardless of ability — can access and use your CMS site.
 ---
 
 # 🧱 CMS Developer