Added Catmandu::Exporter::Table

A few weeks ago I created [Catmandu::Exporter::Table](https://metacpan.org/pod/Catmandu::Exporter::Table). The speed seems to be comparable with Text::TabularDisplay and Text::Table. The speed comparision may not be fair because Catmandu::Exporter::Table expects a different input format (array of hashes instead of array of arrays). Depending on you actual input format, Catmandu::Exporter::Table may be faster.

To give a real life example, convert an Excel table to ASCII with Catmandu::Importer::XLS and Catmandu::Exporter::Table (not preserving column order):

    catmandu convert XLS to Table < excel-file.xls