Add Dev build info for Azure migration

[parapenT1sta]

I think the information for dev build can be also added on this page https://nightscout.github.io/vendors/azure/migrate/ on step J)

Stable nightscout/cgm-remote-monitor:latest

Dev Build nightscout/cgm-remote-monitor:latest_dev

[psonnera]

Yes, there is still so much work to do. I don't like the idea to adding dev at this point but know I need to add dev in other vendors platforms instructions.

[psonnera]

Implementing changes in https://nightscout.github.io/update/dev_branch/ for Railway I believe you're right as Azure (Docker) doesn't use GitHub, so yes. Let me fix that now.

[parapenT1sta]

I am using Dev version and I got the tag from here: https://hub.docker.com/r/nightscout/cgm-remote-monitor/tags

[psonnera]

Yes I know