[SLC] ModifiersBox: add kdoc

^KT-56046

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/modifierLists/ModifiersBox.kt

@@ -5,6 +5,15 @@
 
 package org.jetbrains.kotlin.light.classes.symbol.modifierLists
 
+/**
+ * This class is used as a proxy for [com.intellij.psi.PsiModifierList.hasModifierProperty].
+ *
+ * [LazyModifiersBox] provides an ability to compute each modifier separately to avoid heavy computation.
+ * [SimpleModifiersBox] is a collection of possible modifiers.
+ * [EmptyModifiersBox] just a box without modifiers.
+ *
+ * @see SymbolLightModifierList
+ */
 internal sealed interface ModifiersBox {
     fun hasModifier(modifier: String): Boolean
 }

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/modifierLists/SimpleModifiersBox.kt

@@ -7,5 +7,6 @@ package org.jetbrains.kotlin.light.classes.symbol.modifierLists
 
 internal class SimpleModifiersBox(private val modifiers: Set<String>) : ModifiersBox {
     constructor(vararg modifiers: String) : this(modifiers.toSet())
+
     override fun hasModifier(modifier: String): Boolean = modifier in modifiers
 }