fix: update regular expression to support windows

[ghostwriter]

$ By default, the match must occur at the end of the string or before \n at the end of the string; in multiline mode, it must occur before the end of the line or before \n at the end of the line.
https://docs.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-language-quick-reference

closes #138

[jasonmccreary]

While I understand since I followed the issue, but it seems rather cryptic.

I'd rather use \R instead of \r?$ or normalize $contents beforehand in a similar way.

We should also add a parser test where we pass in a string with Windows line endings to verify this change.

[ghostwriter]

I'd rather use \R instead of \r?$ or normalize $contents beforehand in a similar way.

I have chosen to normalize $contents with str_replace(["\r\n", "\r"], "\n", $content);

We should also add a parser test where we pass in a string with Windows line endings to verify this change.

The test gives a false positive on newer versions of macOS. It must pass on Mac (OS 9 and below) and Windows OS for confidence. (unless I missed something)

[jasonmccreary]

Thanks.