Update doc to use metric units in string format (CleverRaven#33386)

* Update doc to use metric units in string format

* more

* Apply suggestions from code review

Co-Authored-By: Curtis Merrill <[email protected]>

doc/JSON_INFO.md

@@ -831,8 +831,8 @@ See also VEHICLE_JSON.md
 "description" : "Socks. Put 'em on your feet.", // Description of the item
 "phase" : "solid",                // (Optional, default = "solid") What phase it is
 "weight" : 350,                   // Weight of the item in grams. For stackable items (ammo, comestibles) this is the weight per charge.
-"volume" : 1,                     // Volume, measured in 1/4 liters. For stackable items (ammo, comestibles) this is the volume of stack_size charges. Volume in ml and L can be used - "50ml" or "2L"
-"integral_volume" : 0,            // Volume added to base item when item is integrated into another (eg. a gunmod integrated to a gun)
+"volume" : "250 ml",              // Volume, volume in ml and L can be used - "50 ml" or "2 L". For stackable items (ammo, comestibles) this is the volume of stack_size charges.
+"integral_volume" : 0,            // Volume added to base item when item is integrated into another (eg. a gunmod integrated to a gun). Volume in ml and L can be used - "50 ml" or "2 L".
 "integral_weight" : 0,            // Weight added to base item when item is integrated into another (eg. a gunmod integrated to a gun)
 "rigid": false,                   // For non-rigid items volume (and for worn items encumbrance) increases proportional to contents
 "insulation": 1,                  // (Optional, default = 1) If container or vehicle part, how much insulation should it provide to the contents
@@ -940,8 +940,8 @@ Pet armor can be defined like this:
 "environmental_protection" : 0,  //  (Optional, default = 0) How much environmental protection it affords
 "material_thickness" : 1,  // Thickness of material, in millimeter units (approximately).  Generally ranges between 1 - 5, more unusual armor types go up to 10 or more
 "pet_bodytype":        // the body type of the pet that this monster will fit.  See MONSTERS.md
-"max_pet_vol:          // the maximum volume of the pet that will fit into this armor.
-"min_pet_vol:          // the minimum volume of the pet that will fit into this armor.
+"max_pet_vol:          // the maximum volume of the pet that will fit into this armor. Volume in ml and L can be used - "50 ml" or "2 L".
+"min_pet_vol:          // the minimum volume of the pet that will fit into this armor. Volume in ml and L can be used - "50 ml" or "2 L".
 "power_armor" : false, // If this is a power armor item (those are special).
 ```
 Alternately, every item (book, tool, gun, even food) can be used as armor if it has armor_data:
@@ -1076,7 +1076,7 @@ It could also be written as a generic item ("type": "GENERIC") with "armor_data"
 "price": 95,           // Used when bartering with NPCs
 "material": ["iron", "wood"], // Material types.  See materials.json for possible options
 "weight": 907,         // Weight, measured in grams
-"volume": 6,           // Volume, measured in 1/4 liters
+"volume": "1500 ml",   // Volume, volume in ml and L can be used - "50 ml" or "2 L"
 "bashing": 12,         // Bashing damage caused by using it as a melee weapon
 "cutting": 12,         // Cutting damage caused by using it as a melee weapon
 "flags" : ["CHOP"],    // Indicates special effects
@@ -1180,7 +1180,7 @@ Alternately, every item (book, tool, armor, even food) can be used as a gunmod i
 "techniques": "FLAMING", // Combat techniques used by this tool
 "flags": "FIRE",      // Indicates special effects
 "weight": 831,        // Weight, measured in grams
-"volume": 6,          // Volume, measured in 1/4 liters
+"volume": "1500 ml",  // Volume, volume in ml and L can be used - "50 ml" or "2 L"
 "bashing": 12,        // Bashing damage caused by using it as a melee weapon
 "cutting": 0,         // Cutting damage caused by using it as a melee weapon
 "to_hit": 3,          // To-hit bonus if using it as a melee weapon
@@ -1556,8 +1556,8 @@ The contents of use_action fields can either be a string indicating a built-in f
     "type": "holster", // Holster or draw a weapon
     "holster_prompt": "Holster item", // Prompt to use when selecting an item
     "holster_msg": "You holster your %s", // Message to show when holstering an item
-    "max_volume": 6, // Maximum volume of each item that can be holstered
-    "min_volume": 3,  // Minimum volume of each item that can be holstered or 1/3 max_volume if unspecified
+    "max_volume": "1500 ml", // Maximum volume of each item that can be holstered. Volume in ml and L can be used - "50 ml" or "2 L".
+    "min_volume": "750 ml",  // Minimum volume of each item that can be holstered or 1/3 max_volume if unspecified. volume in ml and L can be used - "50 ml" or "2 L".
     "max_weight": 2000, // Maximum weight of each item. If unspecified no weight limit is imposed
     "multi": 1, // Total number of items that holster can contain
     "draw_cost": 10, // Base move cost per unit volume when wielding the contained item
@@ -1772,7 +1772,7 @@ For `type`s: `bionic` and `bionic_group` following enrties can scale the results
     "open": "f_foo_open",
     "bash": "TODO",
     "deconstruct": "TODO",
-    "max_volume": 4000,
+    "max_volume": "1000 L",
     "examine_action": "workbench",
     "workbench": { "multiplier": 1.1, "mass": 10000, "volume": "50L" }
 }
@@ -1824,7 +1824,7 @@ Strength required to move the furniture around. Negative values indicate an unmo
     "move_cost": 10,
     "light_emitted": 10,
     "trap": "spike_pit",
-    "max_volume": 4000,
+    "max_volume": "1000 L",
     "flags": ["TRANSPARENT", "DIGGABLE"],
     "connects_to" : "WALL",
     "close": "t_foo_closed",
@@ -1933,7 +1933,7 @@ Color of the object as it appears in the game. "color" defines the foreground co
 
 #### `max_volume`
 
-(Optional) Maximal volume that can be used to store items here.
+(Optional) Maximal volume that can be used to store items here. Volume in ml and L can be used - "50 ml" or "2 L"
 
 #### `examine_action`