JSON description tweaks

Most of these changes are typo fixes, and that includes English -> American English spelling changes for consistency, wherever I could find them.

archery.json was given a lot of attention, and most of the descriptions have been reworded for better clarity. Also, all instances of 'wood' and 'metal' in the ammo names have been changed to 'wooden' and 'metallic' in better keeping with proper grammar.

It's by no means perfect, but I'm willing to hear suggestions and criticism if something needs work.