Bugfix: collection expression support added

[zbyszekprasak]

In README.md there is example of creating ErrorOr form collection of errors using collection expression but in library no such feature exist. Here is implementation of this feature.

Examples:

ErrorOr<int> result = [Error.Validation(), Error.Validation()];

public ErrorOr<int> MultipleErrorsToErrorOr()
{
    return [
        Error.Validation(description: "Invalid Name"),
        Error.Validation(description: "Invalid Last Name")
    ];
}