Discuss IIS issues in .NET SDK docs

[sergei-pankratov]

The current docs at https://github.com/Fr8org/Fr8Core/blob/docs8/Docs/ForDevelopers/DevelopmentGuides/Terminals/dotNet/TerminalDeveloping-GettingStarted.md
say nothing about IIS, recently there have been some headaches related to this.
add a section that clarifies what we recommend people use and discusses what the alternatives are.

Setting for what projects are set for start up are stored in .suo file (user-specific solution settings file)
If we use IIS Express, then automation of setting up multiple startup is a very complex issue.
There is a very dirty possible solution of commiting .suo file, but it can lead to unexpected results.
.suo file can also be parsed, in theory, and modified.
However it might require to build a VS extenstion, in order to do that.
If we use local IIS then configuring multiple start up is not needed, once IIS is properly configured