Hotfix category, and roll back RTN to 0.1.8 (#192)

* Hotfix categories

Also roll back RTN to 0.1.8 as regression introduced in 0.2

* bump version

src/shared/Extensions/StringExtensions.cs

@@ -1,5 +1,3 @@
-using System.Text.RegularExpressions;
-
 namespace SharedContracts.Extensions;
 
 public static partial class StringExtensions