Add comprehensive sample demo application and tutorial for Optimizely C# SDK#385

Copilot wants to merge 1 commit intomasteroptimizely/csharp-sdk:masterfrom

copilot/fix-ea22db45-008d-4b42-8b94-23b6835c6d75optimizely/csharp-sdk:copilot/fix-ea22db45-008d-4b42-8b94-23b6835c6d75Copy head branch name to clipboard