Fish buff

This makes morale bonuses noticeably easier to get as a Fish.  Still not
perfectly intuitive.
Replaces doubled 556 entry with two types of 40mm grenades.
MOAR BULLITZ
MOAR 556!
Create JSON_FLAGS.md

This file is where flags used in json files will be documented.
Updated.
JSON_FLAGS.md - First round of flags.

This is the first round of flags to be added to JSON_FLAGS.md. Being
added as multiple commits instead of one singular update when done, to
be able to see how Github is parsing the file.
Remove game* parameter from item::tname().
Add item::display_name() and use for inventory and floor-items.
Use display_name() for game::pickup().
Fixes small regression introduced in #4698

martial arts ongethit trigger now works again
Changed some char fields in itype.h to int fields

fixes #4741
More duplicate entries.
Tab removal.
Add mounted NX17 vehicle turret.
Capitalize NX17.
Fix Driving page formatting

Egad! some of my text ran off the side of the screen D:

Fixed now.
Safety check working better

I still haven't got it to display the message when driving with
vehiclesafemode on & hostile, but Web Weaver now works properly.  As in,
safe mode trumps weaving.
Engine note

We ought to let people know that they have to manually turn the key.
Easy to forget!
WHERETO find the ignition

Vagueness is not our friend here.