Add more video demo

Just like what we have done in [Try Request Routing](https://kmesh.net/en/docs/userguide/try_request_routing/) and [Try Traffic Shifting](https://kmesh.net/en/docs/userguide/try_traffic_shifting/), it would be great if there is a video demo after each doc.

Start with the Try Request Routing and Try Traffic Shifting pages linked in the issue, and inspect how their video demos are represented. Identify the documentation pages intended to receive demos and the existing embedding pattern; done means the agreed pages each contain a video demo consistent with those examples.

Written by the indexing model from the issue text.