Adds military-books spawngroup to mil-outpost barracks

Main attraction is the chance of MA manuals for Krav Maga, TKD, Ninjutsu, and (rarely) Eskrima and Pentjak Silat.  A MCMAP MA would eliminate the TKD spawn and probably the Eskrima/Silat ones as well, FWIW, in favor of folks having its book handy.

Other highlights include rifle, SMG, and launcher books, so folks can get the basics down before using ammo.  First aid and swimming are helpful skills to have, too.
Merge pull request #10382 from KA101/MAB

Adds military-books spawngroup to mil-outpost barracks