Add "Will be destroyed when pillaged" unique (#12943)

* Add Will be destroyed when pillaged unique

* Applied the suggestions of yairm210

core/src/com/unciv/models/ruleset/unique/UniqueType.kt

@@ -642,6 +642,7 @@ enum class UniqueType(
     Unpillagable("Unpillagable", UniqueTarget.Improvement),
     PillageYieldRandom("Pillaging this improvement yields approximately [stats]", UniqueTarget.Improvement),
     PillageYieldFixed("Pillaging this improvement yields [stats]", UniqueTarget.Improvement),
+    DestroyedWhenPillaged("Destroyed when pillaged", UniqueTarget.Improvement),
     Irremovable("Irremovable", UniqueTarget.Improvement),
     AutomatedUnitsWillNotReplace("Will not be replaced by automated units", UniqueTarget.Improvement),
     ImprovesResources("Improves [resourceFilter] resource in this tile", UniqueTarget.Improvement, flags = UniqueFlag.setOfNoConditionals,

core/src/com/unciv/ui/screens/worldscreen/unit/actions/UnitActionsPillage.kt

@@ -63,6 +63,11 @@ object UnitActionsPillage {
 
                 if (pillagingImprovement)  // only Improvements heal HP
                     unit.healBy(25)
+                
+                if (tile.getImprovementToPillage()?.hasUnique(UniqueType.DestroyedWhenPillaged) == true) {
+                    tile.removeImprovement()
+                }
+                    
             }.takeIf { unit.hasMovement() && canPillage(unit, tile) }
         )
     }

docs/Modders/uniques.md

@@ -2510,6 +2510,9 @@ Simple unique parameters are explained by mouseover. Complex parameters are expl
 
 	Applicable to: Improvement
 
+??? example  "Will be destroyed when pillaged"
+	Applicable to: Improvement
+
 ??? example  "Irremovable"
 	Applicable to: Improvement