Document the process of auto-generating the SDK from the openapi

[mostaphaRoudsari]

@MingboPeng has done a great job in automating the process and fixing the issues during the translation. We need to document the process and its limitations.

[michaldengusiak]

@MingboPeng I will be very interested in your approach... we are starting a similar step with SAM..
so far I tested Sandcastle and seems to be fine... keys are tags
I can see you have most of them generated so should works file..
I guess we could add a few examples to some functions...in tags
https://docs.microsoft.com/en-us/dotnet/csharp/codedoc

let me know what is your plan so maybe we can follow the same approach