[FEATURE REQ] Documentation around debugging an iotedge application with iotedgedev simulator

### Description.

Suggestion some assistance for debugging or some pointers to documentation.

I did
- `iotedgedev solution build -f deployment.debug.template.json`. .../config/deployment.debug.amd64.json got created
- `iotedgedev iothub setup`.
- `iotedgedev simulator setup -i "HostName=myhub.azure.devices.net;SharedAccessKeyName=iothubowner;SharedAccessKey=xxxSaSxxx"`
- `iotedgedev simulator start`
- failed with ERROR: Deployment manifest config/deployment.amd64.json not found. Please build the solution before starting IoT Edge simulator.
- Renamed /config/deployment.**debug**.amd64.json to /config/deployment.amd64.json **OR**
- iotedgedev solution build -f deployment.debug.template.json
- `iotedgedev simulator start`
- Spined all modules "IoT Edge Simulator has been started in solution mode."

While trying to debug a module.

Exception has occurred: CLR/System.InvalidOperationException
An exception of type 'System.InvalidOperationException' occurred in System.Private.CoreLib.dll but was not handled in user code: **'Environment variable IOTEDGE_WORKLOADURI is required**.'