add docs about windows licensing

[jtriley]

How to "bring your own license" to cloudbase image.

[Milstein]

https://www.youtube.com/watch?v=JMDxpAmR_XQ

[Milstein]

To extend beyond 180 days of Trial period: https://learn.microsoft.com/en-us/answers/questions/133461/windows-server-2019-datacenter-what-happen-after-1.html