books/fdp-primer: Fix table Language Names

Column config was missed from D29573.

Fix some escape chars introduced on
a237bc3c647392fee48479ddf67a6b86c2677f4a.

The \ is being printed in the output, adding a space at the beginning of
the line trick the toc script (not messing the menu) and renders well.

Approved by: carlavilla (doc)
Differential Revision: https://reviews.freebsd.org/D29700