text/vnd.trolltech.linguist: require XML whitespace or closing > in magic
https://doc.qt.io/qt-5/linguist-ts-file-format.html
Avoids some more MPEG TS confusion. Hopefully that is -- I haven't
been able to locate MPEG TS samples that would be misdetected as
linguist files in the first place. But because of that, I think it's
fair to assume that the sequence <TS is not that common in them, and
thus it followed by XML whitespace or the start tag closing > could
be even less common.
Not checking for <TS/ as the root element may not be empty per the
DTD.
Refs #10