Add `followLinks` option in `zipDirectory` and `addDirectory`

In some cases, symbolic links are not desired. Please add this param and just pass it to

archive/lib/src/io/zip_file_encoder.dart

Lines 35 to 36 in 9de7a05

    
           void addDirectory(Directory dir, {bool includeDirName = true, int? level}) { 
        
             List files = dir.listSync(recursive: true);

Zip/tar.. encoders should add this param.

That seems like a good thing to add. Not sure when I'll be able to get to it.

I believe it should be an easy and quick fix to add followLinks in TarFileEncoder.tarDirectory, TarFileEncoder.addDirectory, ZipFileEncoder.zipDirectory and ZipFileEncoder.addDirectory.

If it's okay, I would like to open a pull request.

That would be great, thank you

	void addDirectory(Directory dir, {bool includeDirName = true, int? level}) {
	List files = dir.listSync(recursive: true);