Replace demo gif with mp4

Author: simion

README.md

@@ -7,7 +7,7 @@
 
 **Your local code review assistant** — review GitHub and BitBucket pull requests from your terminal, powered by Claude Code / Gemini / Codex CLI.
 
-![reviewd demo](reviewd_demo.gif)
+<video src="reviewd_demo.mp4" autoplay loop muted playsinline></video>
 
 - Review your team's PRs using Claude, Gemini, or Codex CLI — right from your workstation
 - All local — no CI pipeline, no cloud service, no new accounts