Merge pull request Cysharp#33 from Cysharp/hotfix/CommandLineOptions

Hotfix/command line options

unittest fix

Merge pull request Cysharp#30 from Cysharp/hotfix/ThroughOperationCan…

…celedException

OperationCanceledException by user code should not be handled.

Update ReadMe.md

allow `,`

Merge pull request Cysharp#27 from Cysharp/next-v

Improve array handling, remove Utf8Json dependency

Merge pull request Cysharp#25 from nogic1008/feature/NullableAnnotations

Enable Nullable Reference Type(annotations)

IApplicationLifetime -> IHostApplicationLifetime

Merge pull request Cysharp#19 from Cysharp/feature/ReturnValueAsExitCode

Treat the return value as the exit code.

Merge pull request Cysharp#16 from Cysharp/UpgradeHostingAndNetCore

Upgrade Microsoft.Extensions.Hosting and .NET Core