docs(readme): add demo video section to both READMEs

README.md

@@ -17,6 +17,12 @@ and **Launchpad** through the *real trackpad gesture pathway*, with **controllab
 Built for **end-to-end UI test automation**: it drives the exact system effects a 3/4-finger
 trackpad swipe produces, without a keyboard shortcut and without a physical trackpad.
 
+## Demo
+
+Driving macOS dock-swipe gestures straight from the terminal:
+
+<video src="https://github.com/oomol-lab/dockswipe/raw/main/assets/demo.mp4" controls muted width="100%"></video>
+
 ## Why not a keyboard shortcut or a Spaces API?
 
 | Need | Why dock-swipe fits |

README.zh-CN.md

@@ -16,6 +16,12 @@
 为**端到端 UI 自动化测试**而生：它驱动的正是三/四指触控板 swipe 在系统层产生的效果，
 既不靠快捷键，也不需要真实触控板。
 
+## 演示
+
+直接从命令行驱动 macOS dock-swipe 手势：
+
+<video src="https://github.com/oomol-lab/dockswipe/raw/main/assets/demo.mp4" controls muted width="100%"></video>
+
 ## 为什么不用快捷键 / Spaces API？
 
 | 需求 | dock-swipe 为什么对得上 |