Add docstring

src/DeltaLake/Kernel/State/EngineContext.cs

@@ -18,12 +18,44 @@ namespace DeltaLake.Kernel.State
     /// </summary>
     internal struct EngineContext
     {
+        /// <summary>
+        /// The global table scan state represents progress during a table scan
+        /// shared from the Kernel to us.
+        /// </summary>
         internal unsafe SharedGlobalScanState* GlobalScanState;
+
+        /// <summary>
+        /// The schema represents the read schema of the table shared from the
+        /// Kernel to us.
+        /// </summary>
         internal unsafe SharedSchema* Schema;
+
+        /// <summary>
+        /// A pointer to the root of the table.
+        /// </summary>
         internal unsafe char* TableRoot;
+
+        /// <summary>
+        /// The External Engine represents the external engine (us) we share
+        /// with the Kernel for various callbacks.
+        /// </summary>
         internal unsafe SharedExternEngine* Engine;
+
+        /// <summary>
+        /// Kernel reported list of partitions this Delta Table has.
+        /// </summary>
         internal unsafe PartitionList* PartitionList;
+
+        /// <summary>
+        /// Kernel reported list of values in a partition this Delta Table has.
+        /// </summary>
         internal unsafe CStringMap* PartitionValues;
+
+        /// <summary>
+        /// The ArrowContext holds all state pointers as we load the table from
+        /// Parquet throughout the scan, this is used to expose the actual data
+        /// back to end-users by converting from Arrow to various APIs.
+        /// </summary>
         internal unsafe ArrowContext* ArrowContext;
     }
 }