Add B+Tree Node and Leaf size fine tuning options.

src/ZoneTree/Options/ZoneTreeOptions.cs

@@ -99,6 +99,16 @@ public sealed class ZoneTreeOptions<TKey, TValue>
     /// </summary>
     public BTreeLockMode BTreeLockMode { get; set; } = BTreeLockMode.NodeLevelMonitor;
 
+    /// <summary>
+    /// The B+Tree node size.
+    /// </summary>
+    public int BTreeNodeSize { get; set; } = 128;
+
+    /// <summary>
+    /// The B+Tree leaf size.
+    /// </summary>
+    public int BTreeLeafSize { get; set; } = 128;
+
     /// <summary>
     /// ZoneTree Logger.
     /// </summary>

src/ZoneTree/Segments/InMemory/MutableSegment.cs

@@ -54,7 +54,9 @@ public sealed class MutableSegment<TKey, TValue> : IMutableSegment<TKey, TValue>
 
         BTree = new(Comparer,
             Options.BTreeLockMode,
-            indexOpProvider);
+            indexOpProvider,
+            Options.BTreeNodeSize,
+            Options.BTreeLeafSize);
 
         MarkValueDeleted = options.MarkValueDeleted;
         MutableSegmentMaxItemCount = options.MutableSegmentMaxItemCount;
@@ -73,7 +75,12 @@ public sealed class MutableSegment<TKey, TValue> : IMutableSegment<TKey, TValue>
         Options = options;
         Comparer = options.Comparer;
 
-        BTree = new(Comparer, Options.BTreeLockMode);
+        BTree = new(
+            Comparer,
+            Options.BTreeLockMode,
+            null,
+            Options.BTreeNodeSize,
+            Options.BTreeLeafSize);
         BTree.SetNextOpIndex(nextOpIndex);
 
         MarkValueDeleted = options.MarkValueDeleted;