docs: use video tag with raw URL for demo embedding

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JiaboLi-GitHub

README-CN.md

@@ -23,7 +23,7 @@ renderdoc-mcp 是一个基于 RenderDoc Replay API 的 MCP Server 和 CLI，提
 
 ## 演示
 
-https://github.com/JiaboLi-GitHub/renderdoc-mcp/raw/main/docs/demo/demo.mp4
+<video src="https://github.com/JiaboLi-GitHub/renderdoc-mcp/raw/main/docs/demo/demo.mp4" controls width="100%"></video>
 
 ## 功能概览
 

README.md

@@ -23,7 +23,7 @@ renderdoc-mcp is an MCP server and CLI that wraps the RenderDoc replay API into
 
 ## Demo
 
-https://github.com/JiaboLi-GitHub/renderdoc-mcp/raw/main/docs/demo/demo-en.mp4
+<video src="https://github.com/JiaboLi-GitHub/renderdoc-mcp/raw/main/docs/demo/demo-en.mp4" controls width="100%"></video>
 
 ## Features