Add info about how to call biak for PR `/deploy`

Update the workflow file [here](https://github.com/kurnakovv/biak/blob/dev/.github/workflows/deploy-nuget-for-pr.yml#L98)
<img width="902" height="416" alt="Image" src="https://github.com/user-attachments/assets/5a56e541-8b4f-4938-acec-4bf2e45902d1" />

With this text

> And run it
> ```
> dotnet biak-pr
> ```
