Add some comments for column context and guesses

dat-schema/_Core.gql

@@ -544,9 +544,9 @@ type BaseItemTypes @tags(list: ["item:def", "item:droptable"]) {
  _: bool
  _: rid
  _: rid
- _: bool
+ _: bool # something to do with being transactional/UI based items
  TradeMarketCategory: TradeMarketCategory
- Unmodifiable: bool
+ Unmodifiable: bool # only for base types whose class isn't inherently Unmodifiable
  Achievement: [AchievementItems]
 }
 
@@ -4362,7 +4362,7 @@ type RareMonsterLifeScalingPerLevel {
 
 type Rarity {
  Id: string
- MinMods: i32
+ MinMods: i32 # This doesn't seem right, rare should be 3 not 4
  MaxMods: i32
  _: i32
  MaxPrefix: i32
@@ -4531,7 +4531,7 @@ type SkillGems @tags(list: ["item:def"]) {
  RegularVariant: SkillGems
  GrantedEffectHardMode: GrantedEffects
  _: rid
- _: i32
+ _: i32 # This is tied to gem color: 1=red, 2=green, 3=blue, 4=white
  ItemExperienceType: ItemExperienceTypes
  MtxSlotTypes: [MicrotransactionSkillGemEffectSlotTypes]
 }