docs: add demo video to README

README.md

@@ -11,6 +11,15 @@ experiments, and ongoing tracking of newer Telegram client behavior.
 `gramsrv` is independent and unofficial. It is not affiliated with, endorsed by,
 or sponsored by Telegram or the official Telegram team.
 
+## Demo Video
+
+<p align="center">
+  <video src="docs/assets/telesrv-demo-split-60s.mp4" controls muted playsinline width="100%"></video>
+</p>
+
+If the GitHub Markdown preview does not show the inline player in your browser,
+open the [60-second Desktop and Android demo](docs/assets/telesrv-demo-split-60s.mp4).
+
 ## Highlights
 
 - **One server program to run.** After PostgreSQL and Redis are ready, the Go

README.zh-CN.md

@@ -8,6 +8,15 @@
 
 `gramsrv` 是独立的非官方项目，与 Telegram 官方及其团队没有关联，也未获得其背书或赞助。
 
+## 演示视频
+
+<p align="center">
+  <video src="docs/assets/telesrv-demo-split-60s.mp4" controls muted playsinline width="100%"></video>
+</p>
+
+如果当前浏览器里的 GitHub Markdown 预览没有显示内联播放器，可以直接打开
+[60 秒 Desktop 与 Android 同屏演示](docs/assets/telesrv-demo-split-60s.mp4)。
+
 ## 亮点
 
 - **一个 server 程序即可运行。** PostgreSQL 与 Redis 准备好后，Go server 进程会编排 RSA key 准备、数据库 migration、语言包 seed、MTProto edge、RPC router、updates、media/files 和可靠投递 worker。