Add information about Dev Tunnel real time traffic inspection / monitoring

### Description

VS Dev Tunnels has a really cool Developer Tools like experience for monitoring all incoming traffic into a Dev Tunnels.
Users have to go through a few clicks to launch it though and it's not mentioned on the main dev tunnels API so am unsure how known about this feature is.


Adding info about it on this page would be helpful I think.

### Page URL

https://learn.microsoft.com/en-us/aspnet/core/test/dev-tunnels?view=aspnetcore-7.0#use-a-tunnel&preserve-view=true

### Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/test/dev-tunnels.md

### Document ID

cc01239c-b0fa-599f-506f-810572b43b1f

### Article author

@tdykstra

### Metadata

* ID: cc01239c-b0fa-599f-506f-810572b43b1f
* Service: **aspnet-core**
* Sub-service: **testing**

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