Update README.md

Author: ssg

README.md

@@ -12,7 +12,10 @@ You can download the latest .NET SDK
 at [Microsoft's download page](https://dotnet.microsoft.com/download).
 
 One project requires .NET Framework in order to be built as it's 
-part of a scenario about migrating from .NET Framework to .NET Core. 
+part of a scenario about migrating from .NET Framework to .NET Core. If you're
+on an environment that can't build .NET Framework projects, you can open
+`streetcoder-nowin.slnf` solution filter to filter it out instead of the main
+solution file `streetcoder.sln`.
 
 I used [Visual Studio 2019](https://visualstudio.microsoft.com/vs/)
 whose Community Edition is free, but you should also be able to use 
@@ -26,4 +29,4 @@ if you find it more comfortable.
   function can have variants like `Contains2` and `Contains3` in the source code, but 
   it's listed as `Contains` in all the listings with different varieties. That's 
   intentional to keep the whole source code compilable without any trouble.
-  Some flavors can use a word-based suffix instead of a numeric one.
+  Some flavors can use a word-based suffix instead of a numeric one.