Update README.md (Untranslated "A new class `ProgramTests.cs` was～")#49

hyoshioka0128 wants to merge 2 commits intomicrosoft:mainmicrosoft/mastering-github-copilot-for-dotnet-csharp-developers:mainfrom

hyoshioka0128:patch-36hyoshioka0128/mastering-github-copilot-for-dotnet-csharp-developers:patch-36Copy head branch name to clipboard