[dotnet] Add dotnet projects and examples

+ Sitemap generator I created while learning the dispose pattern
+ Testing project for learning general C#

dotnet/README.md

@@ -0,0 +1,11 @@
+# Dotnet
+
+```bash
+shaunrd0/klips/dotnet/
+├── sitemap     # Custom library to generate sitemaps
+├── testing     # General .NET practice
+└── README.md
+```
+
+All of these projects were created with the `dotnet` CLI on Linux (Kubuntu 20.04).
+They have not been tested on any other platform.