README.md: Added a information about the end of support for the LibSass library

In test and sample projects added support for .NET 10

Now the LibSass build scripts supports Visual Studio 2026

README.md: Added a deprecation message

README.md: Added a Abstractions AS products to the “Who's Using LibSass Host for .NET” section

In test and sample projects added support of .NET 9

Version 1.5.0

Updated a dependencies

Added a `PACKAGE-DESCRIPTION.md` files to NuGet packages

Added a packages that contain a native assemblies for Windows (ARM) and (ARM64)

PackageLicenseFile -> PackageLicenseExpression

Changed a `.gitignore` file

README.md: Added a Core Sass Compiler and CssBuilder to the “Who's Using LibSass Host for .NET” section

README.md: Code of examples has been updated

Version 1.4.0