Update article screenshot and make CTA buttons prominent (#208)

* docs: add demo video and article links to README

Add tweet screenshot for the video demo prominently after the intro,
and link to the full article thread. Replaces the TODO placeholder.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: use article screenshot for README article link

Replace text-only article link with clickable screenshot showing
the article title, preview image, and engagement stats.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: replace demo video screenshot with higher quality version

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: update article screenshot and make CTAs more prominent

- Replace article screenshot with cleaner version showing title/preview
- Replace small <sub> text links with shields.io badge-style buttons
  for "Watch the demo on X" and "Read the full article on X"

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -25,7 +25,7 @@ Agent Orchestrator manages fleets of AI coding agents working in parallel on you
   <img src="docs/assets/demo-video-tweet.png" alt="Agent Orchestrator demo — AI agents building their own orchestrator" width="560">
 </a>
 
-<sub>512 likes · 48 replies · <a href="https://x.com/agent_wrapper/status/2026329204405723180">Watch the demo on X</a></sub>
+<a href="https://x.com/agent_wrapper/status/2026329204405723180"><img src="https://img.shields.io/badge/%E2%96%B6%EF%B8%8F_Watch_the_demo_on_X-black?style=for-the-badge&logo=x&logoColor=white" alt="Watch the demo on X"></a>
 
 </div>
 
@@ -35,7 +35,7 @@ Agent Orchestrator manages fleets of AI coding agents working in parallel on you
   <img src="docs/assets/article-tweet.png" alt="The Self-Improving AI System That Built Itself" width="560">
 </a>
 
-<sub>1.3K likes · 41 replies · <a href="https://x.com/agent_wrapper/status/2025986105485733945">Read the full article on X</a></sub>
+<a href="https://x.com/agent_wrapper/status/2025986105485733945"><img src="https://img.shields.io/badge/%F0%9F%93%96_Read_the_full_article_on_X-black?style=for-the-badge&logo=x&logoColor=white" alt="Read the full article on X"></a>
 
 </div>