Update README.md

remove nv2 demo

Author: mi-CyberDog

README.md

@@ -40,7 +40,6 @@ vcs import . < cyberdog.repos
 | audio_demos             | 语音例程     | https://github.com/jiayy2/audio_demos                  |
 | cyberdog_ai_sports_demo | 运动计数例程 | https://github.com/Ydw-588/cyberdog_ai_sports_demo     |
 | cyberdog_face_demo      | 人脸识别demo | https://github.com/Ydw-588/cyberdog_face_demo          |
-| nav2_demo               | 导航         | https://github.com/duyongquan/nav2_demo                |
 | cyberdog_vp_demo        | 可视化编程   | https://github.com/szh-cn/cyberdog_vp_demo             |
 | cyberdog_action_demo    | 手势动作识别 | https://github.com/liangxiaowei00/cyberdog_action_demo |