Add/fix up xmldocs with clarifications

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableStrongNestedHit.cs

@@ -7,7 +7,7 @@
 namespace osu.Game.Rulesets.Taiko.Objects.Drawables
 {
     /// <summary>
-    /// Used as a nested hitobject to provide <see cref="TaikoStrongJudgement"/>s for <see cref="DrawableTaikoHitObject"/>s.
+    /// Used as a nested hitobject to provide <see cref="TaikoStrongJudgement"/>s for <see cref="DrawableTaikoStrongHitObject{TObject, TNested}"/>s.
     /// </summary>
     public abstract class DrawableStrongNestedHit : DrawableTaikoHitObject
     {

osu.Game.Rulesets.Taiko/Objects/StrongNestedHitObject.cs

@@ -7,6 +7,10 @@
 
 namespace osu.Game.Rulesets.Taiko.Objects
 {
+    /// <summary>
+    /// Base type for nested strong hits.
+    /// Used by <see cref="TaikoStrongHitObject"/>s to represent their strong bonus scoring portions.
+    /// </summary>
     public abstract class StrongNestedHitObject : TaikoHitObject
     {
         public override Judgement CreateJudgement() => new TaikoStrongJudgement();

osu.Game.Rulesets.Taiko/Objects/TaikoStrongHitObject.cs

@@ -7,6 +7,9 @@
 
 namespace osu.Game.Rulesets.Taiko.Objects
 {
+    /// <summary>
+    /// Base class for taiko hitobjects that can become strong (large).
+    /// </summary>
     public abstract class TaikoStrongHitObject : TaikoHitObject
     {
         /// <summary>