Allows extra files to be verified in addition to the primary target.
[Fact]
public Task AppendFile() =>
Verify("Foo", settings)
.AppendFile("sample.png");Will result in two files being verified:
Tests.AppendFile#00.verified.txtcontainingFooTests.AppendFile#sample.verified.png
[Fact]
public Task AppendContentAsFile() =>
Verify("Foo")
.AppendContentAsFile("extra content");Will result in two files being verified:
Tests.AppendContentAsFile#00.verified.txtcontainingFooTests.AppendContentAsFile#01.verified.txtcontainingextra content